Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/039—Macromolecular compounds which are photodegradable, e.g. positive electron resists
  • G03F7/0392—Macromolecular compounds which are photodegradable, e.g. positive electron resists the macromolecular compound being present in a chemically amplified positive photoresist composition
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
  • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
  • C08F220/10—Esters
  • C08F220/12—Esters of monohydric alcohols or phenols
  • C08F220/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
  • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
  • C08F220/10—Esters
  • C08F220/12—Esters of monohydric alcohols or phenols
  • C08F220/16—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms
  • C08F220/18—Esters of monohydric alcohols or phenols of phenols or of alcohols containing two or more carbon atoms with acrylic or methacrylic acids
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
  • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
  • C08F220/10—Esters
  • C08F220/26—Esters containing oxygen in addition to the carboxy oxygen
  • C08F220/28—Esters containing oxygen in addition to the carboxy oxygen containing no aromatic rings in the alcohol moiety
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
  • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
  • C08F220/10—Esters
  • C08F220/34—Esters containing nitrogen, e.g. N,N-dimethylaminoethyl (meth)acrylate
  • C08F220/36—Esters containing nitrogen, e.g. N,N-dimethylaminoethyl (meth)acrylate containing oxygen in addition to the carboxy oxygen, e.g. 2-N-morpholinoethyl (meth)acrylate or 2-isocyanatoethyl (meth)acrylate
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/0045—Photosensitive materials with organic non-macromolecular light-sensitive compounds not otherwise provided for, e.g. dissolution inhibitors
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/0046—Photosensitive materials with perfluoro compounds, e.g. for dry lithography
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/027—Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds
  • G03F7/032—Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds with binders
  • G03F7/033—Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds with binders the binders being polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. vinyl polymers
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/038—Macromolecular compounds which are rendered insoluble or differentially wettable
  • G03F7/0382—Macromolecular compounds which are rendered insoluble or differentially wettable the macromolecular compound being present in a chemically amplified negative photoresist composition
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/039—Macromolecular compounds which are photodegradable, e.g. positive electron resists
  • G03F7/0392—Macromolecular compounds which are photodegradable, e.g. positive electron resists the macromolecular compound being present in a chemically amplified positive photoresist composition
  • G03F7/0397—Macromolecular compounds which are photodegradable, e.g. positive electron resists the macromolecular compound being present in a chemically amplified positive photoresist composition the macromolecular compound having an alicyclic moiety in a side chain
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/20—Exposure; Apparatus therefor
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/20—Exposure; Apparatus therefor
  • G03F7/2041—Exposure; Apparatus therefor in the presence of a fluid, e.g. immersion; using fluid cooling means
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
  • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
  • C08F220/10—Esters
  • C08F220/26—Esters containing oxygen in addition to the carboxy oxygen
  • C08F220/28—Esters containing oxygen in addition to the carboxy oxygen containing no aromatic rings in the alcohol moiety
  • C08F220/283—Esters containing oxygen in addition to the carboxy oxygen containing no aromatic rings in the alcohol moiety and containing one or more carboxylic moiety in the chain, e.g. acetoacetoxyethyl(meth)acrylate
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F220/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride ester, amide, imide or nitrile thereof
  • C08F220/02—Monocarboxylic acids having less than ten carbon atoms; Derivatives thereof
  • C08F220/10—Esters
  • C08F220/34—Esters containing nitrogen, e.g. N,N-dimethylaminoethyl (meth)acrylate
  • C08F220/36—Esters containing nitrogen, e.g. N,N-dimethylaminoethyl (meth)acrylate containing oxygen in addition to the carboxy oxygen, e.g. 2-N-morpholinoethyl (meth)acrylate or 2-isocyanatoethyl (meth)acrylate
  • C08F220/365—Esters containing nitrogen, e.g. N,N-dimethylaminoethyl (meth)acrylate containing oxygen in addition to the carboxy oxygen, e.g. 2-N-morpholinoethyl (meth)acrylate or 2-isocyanatoethyl (meth)acrylate containing further carboxylic moieties
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/16—Coating processes; Apparatus therefor
  • G03F7/162—Coating on a rotating support, e.g. using a whirler or a spinner
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/16—Coating processes; Apparatus therefor
  • G03F7/168—Finishing the coated layer, e.g. drying, baking, soaking
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/20—Exposure; Apparatus therefor
  • G03F7/2002—Exposure; Apparatus therefor with visible light or UV light, through an original having an opaque pattern on a transparent support, e.g. film printing, projection printing; by reflection of visible or UV light from an original such as a printed image
  • G03F7/2004—Exposure; Apparatus therefor with visible light or UV light, through an original having an opaque pattern on a transparent support, e.g. film printing, projection printing; by reflection of visible or UV light from an original such as a printed image characterised by the use of a particular light source, e.g. fluorescent lamps or deep UV light
  • G03F7/2006—Exposure; Apparatus therefor with visible light or UV light, through an original having an opaque pattern on a transparent support, e.g. film printing, projection printing; by reflection of visible or UV light from an original such as a printed image characterised by the use of a particular light source, e.g. fluorescent lamps or deep UV light using coherent light; using polarised light
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/26—Processing photosensitive materials; Apparatus therefor
  • G03F7/30—Imagewise removal using liquid means
  • G03F7/32—Liquid compositions therefor, e.g. developers
  • G03F7/322—Aqueous alkaline compositions
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/26—Processing photosensitive materials; Apparatus therefor
  • G03F7/38—Treatment before imagewise removal, e.g. prebaking

Definitions

• the present invention relates to a resist composition and a method of forming a resist pattern.
• a resist film composed of a resist material is formed on a substrate, and the resist film is subjected to selective exposure, followed by development, thereby forming a resist pattern having a predetermined shape on the resist film.
• a resist material in which the exposed portions of the resist film become soluble in a developing solution is called a positive-type
• a resist material in which the exposed portions of the resist film become insoluble in a developing solution is called a negative-type.
• miniaturization techniques involve shortening the wavelength (increasing the energy) of the exposure light source.
• ultraviolet radiation typified by g-line and i-line radiation
• KrF excimer lasers and ArF excimer lasers are used in mass production.
• lithography techniques that use an exposure light source having a wavelength shorter (energy higher) than these excimer lasers, such as electron beam (EB), extreme ultraviolet radiation (EUV), and X ray.
• Resist materials for use with these types of exposure light sources require lithography properties such as a high resolution capable of reproducing patterns of minute dimensions, and a high level of sensitivity to these types of exposure light sources.
• a chemically amplified composition which includes a base material component that exhibits a changed solubility in a developing solution under the action of acid and an acid-generator component that generates acid upon exposure.
• the developing solution is an alkali developing solution (alkali developing process)
• a chemically amplified positive resist which contains, as a base component (base resin), a resin which exhibits increased solubility in an alkali developing solution under action of acid, and an acid generator is typically used.
• base resin base component
• acid generator an acid generator
• a resist film formed using such a resist composition is selectively exposed at the time of forming a resist pattern, in exposed areas, acid is generated from the acid generator component, and the polarity of the base resin increases by the action of the generated acid, thereby making the exposed areas of the resist film soluble in the alkali developing solution.
• the unexposed portions of the resist film remain to form a positive resist pattern.
• the base resin used for a chemically amplified resist composition contains a plurality of structural units for improving lithography properties and the like.
• a structural unit containing an acid decomposable group which is decomposed by the action of acid generated from an acid generator component and exhibits increased polarity.
• a structural unit containing a lactone-containing cyclic group or a structural unit containing a polar group such as a hydroxy group is used in combination.
• the behavior of acid generated from the acid generator component upon exposure is one of the factors which has large influence on the lithography properties.
• onium salt acid generators such as iodonium salts and sulfonium salts; oxime sulfonate acid generators; diazomethane acid generators; nitrobenzylsulfonate acid generators; iminosulfonate acid generators; and disulfone acid generators are known.
• onium salt acid generators those which have an onium ion such as triphenylsulfonium in the cation moiety are mainly used.
• an alkylsulfonate ion or a fluorinated alkylsulfonate ion in which part or all of the hydrogen atoms within the aforementioned alkylsulfonate ion has been substituted with fluorine atoms is typically used.
• Patent Literature 1 Japanese Patent No. 5149236
• the present invention takes the above circumstances into consideration, with an object of providing a resist composition which enables formation of a resist pattern with improved lithography properties and having a good shape, and a method of forming a resist pattern.
• the present invention employs the following aspects.
• a first aspect of the present invention is a resist composition which generates acid upon exposure and exhibits changed solubility in a developing solution under action of acid
• the resist composition including a resin component (A1) which exhibits changed solubility in a developing solution under action of acid and an acid-generator component (B) which generates acid upon exposure, the resin component (A1) including a structural unit (a0) represented by general formula (a0-1) shown below, the amount of the structural unit (a0) based on the combined total (100 mol %) of all structural units constituting the resin component (A1) being more than 30 mol %, and the acid-generator component (B) containing an acid generator (B1) represented by general formula (b1) shown below.
• R 01 represents a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms;
• Va 01 represents an alkylene group having 1 to 10 carbon atoms;
• Ra 01 represents an acid dissociable group;
• R b01 represents a cyclic hydrocarbon group of 3 to 20 carbon atoms which may have a substituent;
• L b01 represents —O—C( ⁇ O)— or —C( ⁇ O)—O—;
• Y b01 represents a divalent linking group or a single bond;
• V b01 represents a fluorinated alkylene group having 1 to 9 carbon atoms;
• R b02 represents a fluorine atom or a hydrogen atom; provided that the total number of fluorine atoms contained in V b01 and R b02 is 2 or 3;
• m represents an integer of 1 or more; and
• M m+ represents an m-valent organic
• a second aspect of the present invention is a method of forming a resist pattern, including: step (i) of using a resist composition according to the first aspect to form a resist film, step (ii) of exposing the resist film, and step (iii) of developing the exposed resist film to form a resist pattern.
• lithography properties may be improved, and a resist pattern having an improved shape may be formed.
• aliphatic is a relative concept used in relation to the term “aromatic”, and defines a group or compound that has no aromaticity.
• alkyl group includes linear, branched or cyclic, monovalent saturated hydrocarbon, unless otherwise specified. The same applies for the alkyl group within an alkoxy group.
• alkylene group includes linear, branched or cyclic, divalent saturated hydrocarbon, unless otherwise specified.
• a “halogenated alkyl group” is a group in which part or all of the hydrogen atoms of an alkyl group is substituted with a halogen atom.
• the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
• fluorinated alkyl group or a “fluorinated alkylene group” is a group in which part or all of the hydrogen atoms of an alkyl group or an alkylene group have been substituted with a fluorine atom.
• structural unit refers to a monomer unit that contributes to the formation of a polymeric compound (resin, polymer, copolymer).
• the case of describing “may have a substituent” includes both of the case where the hydrogen atom (—H) is substituted with a monovalent group and the case where the methylene group (—CH 2 —) is substituted with a divalent group.
• exposure is used as a general concept that includes irradiation with any form of radiation.
• base component refers to an organic compound capable of forming a film, and is preferably an organic compound having a molecular weight of 500 or more.
• the organic compound used as the base component is broadly classified into non-polymers and polymers. In general, as a non-polymer, any of those which have a molecular weight in the range of 500 to less than 4,000 is used.
• a “low molecular weight compound” refers to a non-polymer having a molecular weight in the range of 500 to less than 4,000.
• any of those which have a molecular weight of 1,000 or more is generally used.
• a “resin” or a “polymer” refers to a polymer having a molecular weight of 1,000 or more.
• the molecular weight of the polymer the weight average molecular weight in terms of the polystyrene equivalent value determined by gel permeation chromatography (GPC) is used.
• a “structural unit derived from an acrylate ester” refers to a structural unit that is formed by the cleavage of the ethylenic double bond of an acrylate ester.
• acrylate ester refers to a compound in which the terminal hydrogen atom of the carboxy group of acrylic acid (CH 2 ⁇ CH—COOH) has been substituted with an organic group.
• the acrylate ester may have the hydrogen atom bonded to the carbon atom on the ⁇ -position substituted with a substituent.
• the substituent (R ⁇ 0 ) that substitutes the hydrogen atom bonded to the carbon atom on the ⁇ -position is an atom other than hydrogen or a group, and examples thereof include an alkyl group of 1 to 5 carbon atoms and a halogenated alkyl group of 1 to 5 carbon atoms.
• a carbon atom on the ⁇ -position of an acrylate ester refers to the carbon atom bonded to the carbonyl group, unless specified otherwise.
• an acrylate ester having the hydrogen atom bonded to the carbon atom on the ⁇ -position substituted with a substituent is sometimes referred to as “ ⁇ -substituted acrylate ester”.
• acrylate esters and ⁇ -substituted acrylate esters are collectively referred to as “( ⁇ -substituted) acrylate ester”.
• a “structural unit derived from acrylamide” refers to a structural unit that is formed by the cleavage of the ethylenic double bond of acrylamide.
• the acrylamide may have the hydrogen atom bonded to the carbon atom on the ⁇ -position substituted with a substituent, and may have either or both terminal hydrogen atoms on the amino group of acrylamide substituted with a substituent.
• a carbon atom on the ⁇ -position of an acrylamide refers to the carbon atom bonded to the carbonyl group, unless specified otherwise.
• a “structural unit derived from hydroxystyrene” refers to a structural unit that is formed by the cleavage of the ethylenic double bond of hydroxystyrene.
• a “structural unit derived from a hydroxystyrene derivative” refers to a structural unit that is formed by the cleavage of the ethylenic double bond of a hydroxystyrene derivative.
• hydroxystyrene derivative includes compounds in which the hydrogen atom at the ⁇ -position of hydroxystyrene has been substituted with another substituent such as an alkyl group or a halogenated alkyl group; and derivatives thereof.
• the derivatives thereof include hydroxystyrene in which the hydrogen atom of the hydroxy group has been substituted with an organic group and may have the hydrogen atom on the ⁇ -position substituted with a substituent; and hydroxystyrene which has a substituent other than a hydroxy group bonded to the benzene ring and may have the hydrogen atom on the ⁇ -position substituted with a substituent.
• the ⁇ -position carbon atom on the ⁇ -position refers to the carbon atom having the benzene ring bonded thereto, unless specified otherwise.
• a “structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative” refers to a structural unit that is formed by the cleavage of the ethylenic double bond of vinylbenzoic acid or a vinylbenzoic acid derivative.
• vinylbenzoic acid derivative includes compounds in which the hydrogen atom at the ⁇ -position of vinylbenzoic acid has been substituted with another substituent such as an alkyl group or a halogenated alkyl group; and derivatives thereof.
• the derivatives thereof include benzoic acid in which the hydrogen atom of the carboxy group has been substituted with an organic group and may have the hydrogen atom on the ⁇ -position substituted with a substituent; and benzoic acid which has a substituent other than a hydroxy group and a carboxy group bonded to the benzene ring and may have the hydrogen atom on the ⁇ -position substituted with a substituent.
• the ⁇ -position carbon atom on the ⁇ -position refers to the carbon atom having the benzene ring bonded thereto, unless specified otherwise.
• styrene derivative includes compounds in which the hydrogen atom at the ⁇ -position of styrene has been substituted with another substituent such as an alkyl group or a halogenated alkyl group; and derivatives thereof.
• the derivatives thereof include hydroxystyrene which has a substituent other than a hydroxy group bonded to the benzene ring and may have the hydrogen atom on the ⁇ -position substituted with a substituent.
• the ⁇ -position carbon atom on the ⁇ -position refers to the carbon atom having the benzene ring bonded thereto, unless specified otherwise.
• a “structural unit derived from styrene” or “structural unit derived from a styrene derivative” refers to a structural unit that is formed by the cleavage of the ethylenic double bond of styrene or a styrene derivative.
• alkyl group as a substituent on the ⁇ -position, a linear or branched alkyl group is preferable, and specific examples include alkyl groups of 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group and a neopentyl group.
• halogenated alkyl group as the substituent on the ⁇ -position include groups in which part or all of the hydrogen atoms of the aforementioned “alkyl group as the substituent on the ⁇ -position” are substituted with halogen atoms.
• halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is particularly desirable.
• hydroxyalkyl group as the substituent on the ⁇ -position include groups in which part or all of the hydrogen atoms of the aforementioned “alkyl group as the substituent on the ⁇ -position” are substituted with a hydroxy group.
• the number of hydroxy groups within the hydroxyalkyl group is preferably 1 to 5, and most preferably 1.
• some structures represented by chemical formulae may have an asymmetric carbon, such that an enantiomer or a diastereomer may be present.
• the one formula represents all isomers.
• the isomers may be used individually, or in the form of a mixture.
• the resist composition of the present embodiment generates acid upon exposure and exhibits changed solubility in a developing solution under action of acid.
• the resist composition of the present embodiment includes a base component (A) (hereafter, referred to as “component (A)”) which exhibits changed solubility in a developing solution under action of acid, and an acid-generator component (B) (hereafter, referred to as “component (B)”) which generates acid upon exposure.
• component (A) base component
• component (B) acid-generator component
• the exposed portions of the resist film are dissolved and removed to form a positive-tone resist pattern in the case of a positive resist, whereas the unexposed portions of the resist film are dissolved and removed to form a negative-tone resist pattern in the case of a negative resist.
• a resist composition which forms a positive resist pattern by dissolving and removing the exposed portions of the resist film is called a positive resist composition
• a resist composition which forms a negative resist pattern by dissolving and removing the unexposed portions of the resist film is called a negative resist composition
• the resist composition of the present embodiment may be either a positive resist composition or a negative resist composition.
• the resist composition may be applied to an alkali developing process using an alkali developing solution in the developing treatment, or a solvent developing process using a developing solution containing an organic solvent (organic developing solution) in the developing treatment, and preferably a solvent developing process.
• the resist composition of the present embodiment is preferably a resist composition which forms a positive pattern in an alkali developing process (i.e, a positive resist compound for alkali developing process) or a resist composition which forms a negative pattern in a solvent developing process (i.e., a negative type resist composition for solvent developing process).
• the component (A) is a base component which exhibits changed solubility in a developing solution under action of acid.
• the term “base component” refers to an organic compound capable of forming a film, and is preferably an organic compound having a molecular weight of 500 or more.
• the organic compound has a molecular weight of 500 or more, the film-forming ability is improved, and a resist pattern of nano level can be easily formed.
• the organic compound used as the base component is broadly classified into non-polymers and polymers.
• any of those which have a molecular weight in the range of 500 to less than 4,000 is used.
• a “low molecular weight compound” refers to a non-polymer having a molecular weight in the range of 500 to less than 4,000.
• any of those which have a molecular weight of 1,000 or more is generally used.
• a “resin” or a “polymer” refers to a polymer having a molecular weight of 1,000 or more.
• the weight average molecular weight in terms of the polystyrene equivalent value determined by gel permeation chromatography (GPC) is used.
• the component (A) contains a resin component (A1) (hereafter, referred to as “component (A1)”) which exhibits changed solubility in a developing solution by the action of acid.
• component (A1) a resin component (hereafter, referred to as “component (A1)”
• the component (A) at least the component (A1) is used, and at least one of another polymeric compound and a low molecular weight compound may be used in combination with the component (A1).
• the component (A1) includes a structural unit (a0) represented by general formula (a0-1) described later. If desired, the component (A1) may include, in addition to the structural unit (a0), other structural unit.
• the structural unit (a0) contains an acid dissociable group (Ra 01 ). Therefore, by using the component (A1), the polarity of the resin component before and after exposure is changed, and a good development contrast may be achieved between the exposed portions of the resist film and the unexposed portions of the resist film not only in an alkali developing process, but also in a solvent developing process.
• the component (A1) is substantially insoluble in an alkali developing solution prior to exposure, but when acid is generated from the component (B) upon exposure, the action of this acid causes an increase in the polarity of the base component, thereby increasing the solubility of the component (A1) in an alkali developing solution. Therefore, in the formation of a resist pattern, by conducting selective exposure of a resist film formed by applying the resist composition to a substrate, the exposed portions of the resist film change from an insoluble state to a soluble state in an alkali developing solution, whereas the unexposed portions of the resist film remain insoluble in an alkali developing solution, and hence, a positive resist pattern is formed by alkali developing.
• the component (A1) exhibits high solubility in an organic developing solution prior to exposure, and when acid is generated from the component (B) upon exposure, the polarity of the component (A1) is increased by the action of the generated acid, thereby decreasing the solubility of the component (A1) in an organic developing solution. Therefore, in the formation of a resist pattern, by conducting selective exposure of a resist film formed by applying the resist composition to a substrate, the exposed portions of the resist film changes from an soluble state to an insoluble state in an organic developing solution, whereas the unexposed portions of the resist film remain soluble in an organic developing solution. As a result, by conducting development using an organic developing solution, thereby forming a negative resist pattern.
• the structural unit (a0) is a structural unit represented by general formula (a0-1) shown below.
• the terminal group (Ra 01 ) on the side chain in formula (a0-1) is an acid dissociable group. This acid dissociable group protects the oxy group (—O—) side of the carbonyloxy group [—C( ⁇ O)—O—] in formula (a0-1).
• An “acid dissociable group” exhibits acid dissociability such that the bond between the acid dissociable group and the adjacent oxygen atom (O) is cleaved by the action of acid.
• a polar group which exhibits a higher polarity than the acid dissociable group is generated, and the polarity is increased.
• the polarity of the entire component (A1) is increased.
• the solubility in an alkali developing solution changes, and the solubility in an alkali developing solution is relatively increased, whereas the solubility in an organic developing solution is relatively decreased.
• R 01 represents a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms;
• Va 01 represents an alkylene group having 1 to 10 carbon atoms; and
• Ra 01 represents an acid dissociable group.
• R 01 represents a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms.
• alkyl group of 1 to 5 carbon atoms for R 01 a linear or branched alkyl group of 1 to 5 carbon atoms is preferable, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group and a neopentyl group.
• the halogenated alkyl group of 1 to 5 carbon atoms represented by R is a group in which part or all of the hydrogen atoms of the aforementioned alkyl group of 1 to 5 carbon atoms have been substituted with halogen atoms.
• the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is particularly desirable.
• R 01 an alkyl group of 1 to 5 carbon atoms or a fluorinated alkyl group of 1 to 5 carbon atoms is preferable, and in terms of industrial availability, a hydrogen atom or a methyl group is more preferable, and a methyl group is still more preferable.
• Va 01 represents an alkylene group having 1 to 10 carbon atoms.
• the alkylene group for Va 01 may be chain or cyclic.
• a chain alkylene group may be linear or branched.
• the linear alkylene group has 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms, still more preferably 1 to 3 carbon atoms, and most preferably 1 carbon atom (a methylene group).
• Specific examples of the linear alkylene group include a methylene group [—CH 2 —], an ethylene group [—(CH 2 ) 2 —], a trimethylene group [—(CH 2 ) 3 —], a tetramethylene group [—(CH 2 ) 4 -] and a pentamethylene group [—(CH 2 ) 5 —].
• the branched alkylene group has 2 to 10 carbon atoms, preferably 3 to 6 carbon atoms, more preferably 3 or 4 carbon atoms, and still more preferably 3 carbon atoms.
• Specific examples of the branched alkylene group include an alkylalkylene group, such as an alkylmethylene group (e.g., —CH(CH 3 )—, —CH(CH 2 CH 3 )—, —C(CH 3 ) 2 —, —C(CH 3 )(CH 2 CH 3 )—, —C(CH 3 )(CH 2 CH 2 CH 3 )— or —C(CH 2 CH 3 ) 2 —); an alkylethylene group (e.g., —CH(CH 3 )CH 2 —, —CH(CH 3 )CH(CH 3 )—, —C(CH 3 ) 2 CH 2 —, —CH(CH 2 CH 3 )CH 2 — or —C(CH 2 CH 3 ) 2 —
• the cyclic alkylene group may be a polycyclic group or a monocyclic group.
• the monocyclic alkylene group a group in which 2 hydrogen atoms have been removed from a monocycloalkane is preferable.
• the monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane.
• the polycyclic alkylene group a group in which 2 hydrogen atoms have been removed from a polycycloalkane is preferable, and the polycyclic group preferably has 7 to 10 carbon atoms. Examples of the polycycloalkane include adamantane, norbomane, isobomane and tricyclodecane.
• Va 01 a chain alkylene group is preferable, and a linear alkylene group is more preferable.
• Ra 01 represents an acid dissociable group.
• Examples of the acid dissociable group for Ra 01 include groups which have been proposed as acid dissociable groups for the base resin of a conventional chemically amplified resist composition.
• acid dissociable groups for the base resin of a conventional chemically amplified resist composition include “acetal-type acid dissociable group” and “tertiary alkyl ester-type acid dissociable group”.
• acetal-type acid dissociable group for Ra 01 examples include an acid dissociable group represented by general formula (a1-r-1) shown below (hereafter, sometimes referred to as “acetal-type acid dissociable group”).
• Ra′ 1 and Ra′ 2 each independently represents a hydrogen atom or an alkyl group
• Ra′ 3 represents a hydrocarbon group, provided that Ra′ 3 may be bonded to Ra′ 1 or Ra′ 2 to form a ring.
• Ra′ 1 and Ra′ 2 represent a hydrogen atom
• both of Ra′ 1 and Ra′ 2 represent a hydrogen atom
• Ra′ 1 or Ra′ 2 is an alkyl group
• the same alkyl groups as those described above the for the substituent which may be bonded to the carbon atom on the ⁇ -position of the aforementioned ⁇ -substituted acrylate ester can be mentioned, and an alkyl group of 1 to 5 carbon atoms is preferable. Specific examples include linear or branched alkyl groups.
• alkyl group examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group and a neopentyl group.
• a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.
• examples of the hydrocarbon group for Ra′ 3 include a linear or branched alkyl group and a cyclic hydrocarbon group.
• the linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and still more preferably 1 or 2 carbon atoms.
• Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group and an n-pentyl group.
• a methyl group, an ethyl group or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.
• the branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms.
• Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group a 1,1-diethylpropyl group and a 2,2-dimethylbutyl group.
• an isopropyl group is preferable.
• the cyclic hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be polycyclic or monocyclic.
• the monocyclic aliphatic hydrocarbon group a group in which 1 hydrogen atom has been removed from a monocycloalkane is preferable.
• the monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane.
• the polycyclic aliphatic hydrocarbon group a group in which 1 hydrogen atom has been removed from a polycycloalkane is preferable, and the polycyclic group preferably has 7 to 12 carbon atoms.
• the polycycloalkane include adamantane, norbornane, isobomane, tricyclodecane and tetracyclododecane.
• the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.
• the aromatic ring is not particularly limited, as long as it is a cyclic conjugated compound having (4n+2) ⁇ electrons, and may be either monocyclic or polycyclic.
• the aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, and still more preferably 6 to 15 carbon atoms, and most preferably 6 to 12 carbon atoms.
• aromatic ring examples include aromatic hydrocarbon rings, such as benzene, naphthalene, anthracene and phenanthrene; and aromatic hetero rings in which part of the carbon atoms constituting the aforementioned aromatic hydrocarbon rings has been substituted with a hetero atom.
• hetero atom within the aromatic hetero rings include an oxygen atom, a sulfur atom and a nitrogen atom.
• aromatic hetero ring include a pyridine ring and a thiophene ring.
• aromatic hydrocarbon group for Ra′ 3 examples include a group in which one hydrogen atom has been removed from the aforementioned aromatic hydrocarbon ring or aromatic hetero ring (aryl group or heteroaryl group); a group in which one hydrogen atom has been removed from an aromatic compound having two or more aromatic rings (biphenyl, fluorene or the like); and a group in which one hydrogen atom of the aforementioned aromatic hydrocarbon ring or aromatic hetero ring has been substituted with an alkylene group (an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group).
• the alkylene group bonded to the aforementioned aromatic hydrocarbon ring or the aromatic hetero ring preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and most
• the cyclic hydrocarbon group for Ra′ 3 may have a substituent.
• substituents include —R P1 , —R P2 —O—R P1 , —R P2 —CO—R P1 , —R P2 —CO—OR P1 , —R P2 —O—CO—R P1 , —R P2 —OH, —R P2 —CN or —R P2 —COOH (hereafter, these substituents are sometimes collectively referred to as “Ra 05 ”).
• R P1 is a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms.
• R P2 is a single bond, a divalent chain saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms.
• a portion or all of the hydrogen atoms having the chain saturated hydrocarbon group, the aliphatic cyclic saturated hydrocarbon group, and the aromatic hydrocarbon group for R P1 and R P2 may be substituted with a fluorine atom.
• the saturated aliphatic cyclic hydrocarbon group may have 1 or more substituents of 1 kind, or 1 or more substituents of a plurality of kinds.
• Examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group and a decyl group.
• Examples of the monovalent saturated cyclic hydrocarbon group having 3 to 20 carbon atoms include a saturated monocyclic aliphatic hydrocarbon group, such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group or a cyclododecyl group; and a saturated polycyclic aliphatic hydrocarbon group, such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.02,6]decanyl group, a tricyclo[3.3.1.13,7]decanyl group, a tetracyclo[6.2.1.13,6.02,7]dodecanyl group or an adamantyl group.
• a saturated monocyclic aliphatic hydrocarbon group such
• Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene.
• the cyclic group is preferably a 4 to 7-membered ring, and more preferably a 4 to 6-membered ring.
• Specific examples of the cyclic group include tetrahydropyranyl group and tetrahydrofuranyl group.
• Examples of the tertiary alkyl ester-type acid dissociable group for Ra 01 include an acid dissociable group represented by general formula (a1-r-2) shown below.
• tertiary ester-type acid dissociable group a group which is constituted of alkyl groups is referred to as “tertiary ester-type acid dissociable group”.
• Ra′ 4 to Ra′ 6 each independently represents a hydrocarbon group, provided that Ra′ 5 and Ra′ 6 may be mutually bonded to form a ring.
• Examples of the hydrocarbon group for Ra′ 4 include a linear or branched alkyl group, a chain or cyclic alkenyl group, and a cyclic hydrocarbon group.
• the linear or branched alkyl group and the cyclic hydrocarbon group (monocyclic aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group or aromatic hydrocarbon group) for Ra′ 4 are the same as defined for Ra′ 3 .
• the chain or cyclic alkenyl group for Ra′ 4 is preferably an alkenyl group having 2 to 10 carbon atoms.
• the hydrocarbon group for Ra′ 5 and Ra′ 6 is the same as defined for Ra′ 3 .
• tertiary alkyl ester-type acid dissociable group for Ra 01 include a group represented by general formula (a1-r2-1) shown below, a group represented by general formula (a1-r2-2) shown below, a group represented by general formula (a1-r2-3) shown below and a group represented by general formula (a1-r2-4) shown below.
• Ra′ 10 represents a linear or branched alkyl group having 1 to 12 carbon atoms optionally having part thereof substituted with a halogen atom or a hetero atom-containing group;
• Ra′ 11 is a group which forms an aliphatic cyclic group together with a carbon atom having Ra′ 10 bonded thereto.
• Ya represents a carbon atom
• Xa represents a group which forms a cyclic hydrocarbon group together with Ya, provided that part or all of the hydrogen atoms of the cyclic hydrocarbon group may be substituted
• Ra 01 to Ra 03 each independently represents a hydrogen atom, a monovalent saturated chain hydrocarbon group of 1 to 10 carbon atoms or a monovalent saturated aliphatic cyclic hydrocarbon group of 3 to 20 carbon atoms, provided that part or all of the hydrogen atoms of the saturated chain hydrocarbon or the saturated aliphatic cyclic hydrocarbon may be substituted
• two or more of Ra 01 to Ra 03 may be mutually bonded to form a cyclic structure
• Yaa represents a carbon atom
• Xaa represents a group which forms an aliphatic cyclic group together with Yaa
• Ra 04 represents an aromatic hydrocarbon group which may have a substituent
• Ra′ 12 and Ra′ 13 each independently represents
• Ra′ 10 represents a linear or branched alkyl group having 1 to 12 carbon atoms optionally having part thereof substituted with a halogen atom or a hetero atom-containing group.
• the linear alkyl group for Ra′ 10 has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and more preferably 1 to 5 carbon atoms.
• Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group and an n-pentyl group.
• a methyl group, an ethyl group or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.
• the branched alkyl group for Ra′ 10 preferably has 3 to 10 carbon atoms, and more preferably 3 to 6 carbon atoms.
• Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, a 1,1-dimethylbutyl group, a 1,1-dimethylpentyl group and a 2,2-dimethylbutyl group.
• an isopropyl group or a tert-butyl group is preferable.
• the alkyl group for Ra′ 10 may have part thereof substituted with a halogen atom or a hetero atom-containing group.
• part of the hydrogen atoms constituting the alkyl group may be substituted with a halogen atom or a hetero atom-containing group.
• part of the carbon atoms constituting the alkyl group e.g., a methylene group
• Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
• Examples of the hetero atom include an oxygen atom, a sulfur atom and a nitrogen atom.
• Examples of the hetero atom-containing group include an oxygen atom (—O—), —C( ⁇ O)—O—, —O—C( ⁇ O)—, —C( ⁇ O)—, —O—C( ⁇ O)—O—, —C( ⁇ O)—NH—, —NH—, —S—, —S( ⁇ O) 2 — and —S( ⁇ O) 2 —O—.
• Ra′ 11 an aliphatic cyclic group formed together with the carbon atom to which Ra′ 10 is bonded
• the monocyclic or polycyclic aliphatic hydrocarbon group a group in which 1 hydrogen atom has been removed from a monocycloalkane or a group in which 1 hydrogen atom has been removed from a polycycloalkane described above for Ra′ 3 in the aforementioned formula (a1-r-1) is preferable.
• the aliphatic cyclic group may be an unsaturated aliphatic cyclic group, and examples thereof include a group in which 1 hydrogen atom has been removed from a monocycloalkene, and a group in which 1 hydrogen atom has been removed from a polycycloalkene.
• the aliphatic cyclic group for Ra′ 11 may have a substituent, and examples thereof include the substituent (Ra 05 ) described above in relation to the cyclic hydrocarbon group for Ra′ 3 , a divalent group which substitutes 2 hydrogen atoms of a methylene group (—CH 2 —) (such as a methylidene group ( ⁇ CH 2 ) or an ethylidene group).
• a group in which the divalent group is bonded at an ⁇ -position of the tertiary carbon atom in formula (a1-r2-1) is preferable.
• an aliphatic cyclic group which is formed of Xa together with Ya is a monocyclic or polycyclic aliphatic hydrocarbon group described above in relation to Ra′ 3 in the aforementioned formula (a1-r-1).
• the cyclic hydrocarbon group which Xa forms with Ya may have a substituent.
• substituents include the same substituents as those which the cyclic hydrocarbon group for Ra′ 3 may have.
• examples of the monovalent saturated chain hydrocarbon group of 1 to 10 carbon atoms for Ra 01 to Ra 03 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group and a decyl group.
• Examples of the monovalent saturated cyclic hydrocarbon group having 3 to 20 carbon atoms for Ra 01 to Ra 03 include a saturated monocyclic aliphatic hydrocarbon group, such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group or a cyclododecyl group; and a saturated polycyclic aliphatic hydrocarbon group, such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.02,6]decanyl group, a tricyclo[3.3.1.13,7]decanyl group, a tetracyclo[6.2.1.13,6.02,7]dodecanyl group or an adamantyl group.
• Ra 01 to Ra 03 is preferably a hydrogen atom or a monovalent saturated hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and most preferably a hydrogen atom.
• Examples of the group containing a carbon-carbon double bond which is generated by forming a cyclic structure in which two or more of Ra 01 to Ra 03 are bonded to each other include a cyclopentenyl group, a cyclohexenyl group, a methyl cyclopentenyl group, a methyl cyclohexenyl group, a cyclopentylideneethenyl group, and a cyclohexylidenethenyl group.
• a cyclopentenyl group, a cyclohexenyl group or a cyclopentylidenyl group is preferable.
• an aliphatic cyclic group which is formed of Xaa together with Yaa is preferably a group exemplified as an aliphatic hydrocarbon group which is a monocyclic group or a polycyclic group of Ra′ 3 in general formula (a1-r-1).
• examples of the aromatic hydrocarbon group for Ra 04 include a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 5 to 30 carbon atoms.
• Ra 04 is preferably a group obtained by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, anthracene, or phenanthrene is further preferable, a group obtained by removing one or more hydrogen atoms from benzene, naphthalene, or anthracene is still further preferable, a group obtained by removing one or more hydrogen atoms from benzene and naphthalene is particularly preferable, and a group obtained by removing one or more hydrogen atoms from benzene is most preferable.
• Examples of the substituent that Ra 04 in general formula (a1-r2-3) may have include a methyl group, an ethyl group, a propyl group, a hydroxyl group, a carboxyl group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, or the like), an alkoxy group (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, or the like), and an alkyloxycarbonyl group.
• a methyl group an ethyl group, a propyl group, a hydroxyl group, a carboxyl group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, or the like), an alkoxy group (a methoxy group, an ethoxy group, a propoxy group, a butoxy group, or the like), and an alkyloxycarbonyl group.
• Ra′ 12 and Ra′ 13 each independently represent a monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms or a hydrogen atom.
• examples of the monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms include the same monovalent chain saturated hydrocarbon group having 1 to 10 carbon atoms as that for Ra 01 to Ra 03 , provided that part or all of the hydrogen atoms of the saturated hydrocarbon group may be substituted;
• Ra′ 12 and Ra′ 13 a hydrogen atom and an alkyl group having 1 to 5 carbon atoms are preferable, an alkyl group having 1 to 5 carbon atoms is further preferable, a methyl group and an ethyl group are still further preferable, and a methyl group is particularly preferable.
• examples of the substituent include the same group as that of Ra 05 .
• Ra′ 14 is a hydrocarbon group which may have a substituent.
• Examples of the hydrocarbon group for Ra′ 14 include a linear or branched alkyl group and a cyclic hydrocarbon group.
• the linear alkyl group for Ra′ 14 preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and still more preferably 1 or 2 carbon atoms.
• Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group and an n-pentyl group.
• a methyl group, an ethyl group or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.
• the branched alkyl group for Ra′ 14 preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specific examples include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group a 1,1-diethylpropyl group and a 2,2-dimethylbutyl group. Among these, an isopropyl group is preferable.
• the cyclic hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be polycyclic or monocyclic.
• the monocyclic aliphatic hydrocarbon group a group in which 1 hydrogen atom has been removed from a monocycloalkane is preferable.
• the monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane.
• the polycyclic aliphatic hydrocarbon group a group in which 1 hydrogen atom has been removed from a polycycloalkane is preferable, and the polycyclic group preferably has 7 to 12 carbon atoms.
• the polycycloalkane include adamantane, norbornane, isobomane, tricyclodecane and tetracyclododecane.
• Ra′ 14 examples include the same aromatic hydrocarbon groups as those described above for Ra 04 .
• Ra′ 14 is preferably a group formed by removing one or more hydrogen atoms from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group formed by removing one or more hydrogen atoms from benzene, naphthalene, anthracene, or phenanthrene, still more preferably a group formed by removing one or more hydrogen atoms from benzene, naphthalene, or anthracene, still more preferably a group formed by removing one or more hydrogen atoms from naphthalene or anthracene, and most preferably a group formed by removing one or more hydrogen atoms from naphthalene.
• Examples of the substituent that Ra′ 14 may have include the same group as the substituent that Ra 04 may have.
• Ra′ 14 in general formula (a1-r2-4) is a naphthyl group
• a position which is bonded to a tertiary carbon atom in general formula (a1-r2-4) may be 1-position and 2-position of the naphthyl group.
• Ra′ 14 in general formula (a1-r2-4) is an anthryl group
• a position which is bonded to a tertiary carbon atom in general formula (a1-r2-4) may be any one of 1-position, 2-position, and 9-position of the anthryl group.
• Ra′ 14 may be bonded to Ra′ 13 to form a condensed ring which may contain a hetero atom.
• Examples of the ring structure of the condensed ring formed by Ra′ 14 bonded to Ra′ 13 include a condensed ring of an alicyclic hydrocarbon group and an aromatic hydrocarbon group.
• the condensed ring may contain a hetero atom.
• Examples of the hetero atom include an oxygen atom, a sulfur atom and a nitrogen atom.
• the ring structure of the alicyclic hydrocarbon portion may be monocyclic or polycyclic, and may contain a hetero atom.
• the ring structure of the aromatic hydrocarbon portion may be monocyclic or polycyclic, and may contain a hetero atom.
• Ra 01 a tertiary alkyl ester-type acid dissociable group is preferable, a group represented by the aforementioned general formula (a1-r2-1) or a group represented by the aforementioned general formula (a1-r2-4) is more preferable, and a group represented by the aforementioned general formula (a1-r2-1) is still more preferable.
• R ⁇ represents a hydrogen atom, a methyl group or a trifluoromethyl group.
• the structural unit (a0) at least one member selected from the group consisting of structural units represented by chemical formulae (a0-1-1) to (a0-1-9) is preferable, and at least one member selected from the group consisting of structural units represented by chemical formulae (a0-1-1), (a0-1-2), (a0-1-5), (a0-1-6) and (a0-1-7) is more preferable.
• structural unit (a0) contained in the component (A1) 1 kind of structural unit may be used, or 2 or more kinds of structural units may be used.
• the amount of the structural unit (a0) based on the combined total (100 mol %) of all structural units constituting the component (A1) is more than 30 mol %, preferably more than 30 mol % to 60 mol %, more preferably 30.5 mol % to 55 mol %, and still more preferably 31 mol % to 50 mol %.
• the amount of the structural unit (a0) is more than the lower limit of the above range, a resist pattern may be reliably obtained, and various lithography properties such as resolution and roughness may be further improved.
• the amount is no more than the upper limit of the above preferable range, a good balance may be achieved with the other structural units.
• the component (A1) may include, in addition to the structural unit (a0), other structural unit.
• Examples of other structural units include a structural unit (a1) containing an acid decomposable group that exhibits increased polarity by the action of acid, (provided that the structural unit (a0) is excluded); a structural unit (a2) containing a lactone-containing cyclic group, an —SO 2 — containing cyclic group or a carbonate-containing cyclic group; a structural unit (a3) containing a polar group-containing aliphatic hydrocarbon group (provided that the structural units (a0), (a1) and (a2) are excluded); a structural unit (a4) containing an acid non-dissociable aliphatic cyclic group; a structural unit (a10) represented by general formula (a10-1); and a structural unit derived from styrene or a derivative thereof.
• the component (A1) may include a structural unit (a1) containing an acid decomposable group that exhibits increased polarity by the action of acid (provided that structural units which fall under the definition of the structural unit (a0) is excluded).
• the term “acid decomposable group” refers to a group in which at least a part of the bond within the structure thereof is cleaved by the action of an acid.
• Examples of acid decomposable groups which exhibit increased polarity by the action of an acid include groups which are decomposed by the action of an acid to form a polar group.
• Examples of the polar group include a carboxy group, a hydroxy group, an amino group and a sulfo group (—SO 3 H).
• a polar group containing —OH in the structure thereof (hereafter, referred to as “OH-containing polar group”) is preferable, a carboxy group or a hydroxy group is more preferable, and a carboxy group is particularly desirable.
• an acid decomposable group a group in which the aforementioned polar group has been protected with an acid dissociable group (such as a group in which the hydrogen atom of the OH-containing polar group has been protected with an acid dissociable group) can be given.
• the “acid dissociable group” refers to both (i) a group in which the bond between the acid dissociable group and the adjacent atom is cleaved by the action of acid; and (ii) a group in which one of the bonds is cleaved by the action of acid, and then a decarboxylation reaction occurs, thereby cleaving the bond between the acid dissociable group and the adjacent atom.
• the acid dissociable group that constitutes the acid decomposable group is a group which exhibits a lower polarity than the polar group generated by the dissociation of the acid dissociable group.
• a polar group exhibiting a higher polarity than that of the acid dissociable group is generated, thereby increasing the polarity.
• the polarity of the entire component (A1) is increased.
• any of those which have been proposed as acid dissociable groups for a base resin of a chemically amplified resist may be mentioned.
• acid dissociable groups for the base resin of a conventional chemically amplified resist include the aforementioned “acetal-type acid dissociable group”, the aforementioned “tertiary alkyl ester-type acid dissociable group” and “tertiary alkyloxycarbonyl acid dissociable group” described below.
• Examples of the acid dissociable group for protecting a hydroxy group as a polar group include the acid dissociable group represented by general formula (a1-r-3) shown below (hereafter, for convenience, referred to as “tertiary alkyloxycarbonyl-type acid dissociable group”).
• Ra′ 7 to Ra′ 9 each independently represents an alkyl group.
• each of Ra′ 7 to Ra′ 9 is preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms. Further, the total number of carbon atoms in the alkyl groups is preferably 3 to 7, more preferably 3 to 5, and still more preferably 3 or 4.
• Examples of the structural unit (a1) include a structural unit derived from an acrylate ester which may have the hydrogen atom bonded to the carbon atom on the ⁇ -position substituted with a substituent (provided that the structural unit (a0) is excluded); a structural unit derived from an acrylamide; a structural unit derived from hydroxystyrene or a hydroxystyrene derivative in which at least a part of the hydrogen atom of the hydroxy group is protected with a substituent containing an acid decomposable group; and a structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative in which at least a part of the hydrogen atom within —C( ⁇ O)—OH is protected with a substituent containing an acid decomposable group.
• the structural unit (a1) a structural unit derived from an acrylate ester which may have the hydrogen atom bonded to the carbon atom on the ⁇ -position substituted with a substituent is preferable.
• preferable structural units for the structural unit (a1) include structural units represented by general formula (a1-1) or (a1-2) shown below (provided that the structural unit (a0) is excluded).
• R represents a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms;
• Va 1 represents a divalent hydrocarbon group which may contain an ether bond;
• n a1 represents an integer of 0 to 2; and
• Ra 1 represents an acid dissociable group represented by the aforementioned formula (a1-r-1) or (a1-r-2).
• Wa 1 represents a hydrocarbon group having a valency of n a2 +1;
• n a2 represents an integer of 1 to 3; and
• Ra 2 represents an acid dissociable group represented by the aforementioned formula (a1-r-1) or (a1-r-3).
• a linear or branched alkyl group of 1 to 5 carbon atoms is preferable, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group and a neopentyl group.
• the halogenated alkyl group of 1 to 5 carbon atoms represented by R is a group in which part or all of the hydrogen atoms of the aforementioned alkyl group of 1 to 5 carbon atoms have been substituted with halogen atoms.
• the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is particularly desirable.
• R a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a fluorinated alkyl group of 1 to 5 carbon atoms is preferable, and a hydrogen atom or a methyl group is particularly desirable in terms of industrial availability.
• Va 1 represents a divalent hydrocarbon group which may have an ether bond.
• the divalent hydrocarbon group for Va 1 may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
• the aliphatic hydrocarbon group as the divalent hydrocarbon group for Va 1 may be either saturated or unsaturated. In general, the aliphatic hydrocarbon group is preferably saturated.
• aliphatic hydrocarbon group a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group containing a ring in the structure thereof can be given.
• the linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, still more preferably 1 to 4, and most preferably 1 to 3.
• a linear alkylene group is preferable. Specific examples thereof include a methylene group [—CH 2 —], an ethylene group [—(CH 2 ) 2 —], a trimethylene group [—(CH 2 ) 3 —], a tetramethylene group [—(CH 2 ) 4 -] and a pentamethylene group [—(CH 2 ) 5 —].
• the branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms.
• branched alkylene groups are preferred, and specific examples include various alkylalkylene groups, including alkylmethylene groups such as —CH(CH 3 )—, —CH(CH 2 CH 3 )—, —C(CH 3 ) 2 —, —C(CH 3 )(CH 2 CH 3 )—, —C(CH 3 )(CH 2 CH 2 CH 3 )—, and —C(CH 2 CH 3 ) 2 —; alkylethylene groups such as —CH(CH 3 )CH 2 —, —CH(CH 3 )CH(CH 3 )—, —C(CH 3 ) 2 CH 2 —, —CH(CH 2 CH 3 )CH 2 —, and —C(CH 2 CH 3 ) 2 —CH 2 —; alkyltrimethylene groups such as —CH(CH 3 )CH 2 CH 2 —, and —CH 2 CH(CH 3 )CH 2 —; and
• an alicyclic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), a group in which the alicyclic hydrocarbon group is bonded to the terminal of the aforementioned chain-like aliphatic hydrocarbon group, and a group in which the alicyclic group is interposed within the aforementioned linear or branched aliphatic hydrocarbon group, can be given.
• the linear or branched aliphatic hydrocarbon group is the same as defined for the aforementioned linear aliphatic hydrocarbon group or the aforementioned branched aliphatic hydrocarbon group.
• the alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
• the alicyclic hydrocarbon group may be either a monocyclic group or a polycyclic group.
• the monocyclic aliphatic hydrocarbon group a group in which 2 hydrogen atoms have been removed from a monocycloalkane is preferable.
• the monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane.
• the polycyclic group a group in which two hydrogen atoms have been removed from a polycycloalkane is preferable, and the polycyclic group preferably has 7 to 12 carbon atoms. Examples of the polycycloalkane include adamantane, norbornane, isobomane, tricyclodecane and tetracyclododecane.
• the aromatic hydrocarbon group as the divalent hydrocarbon group for Va 1 is a hydrocarbon group having an aromatic ring.
• the aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, still more preferably 5 to 20, still more preferably 6 to 15, and most preferably 6 to 10.
• the number of carbon atoms within a substituent(s) is not included in the number of carbon atoms of the aromatic hydrocarbon group.
• aromatic hydrocarbon groups examples include aromatic hydrocarbon rings, such as benzene, biphenyl, fluorene, naphthalene, anthracene and phenanthrene; and aromatic hetero rings in which part of the carbon atoms constituting the aforementioned aromatic hydrocarbon rings has been substituted with a hetero atom.
• aromatic hetero rings examples include an oxygen atom, a sulfur atom and a nitrogen atom.
• aromatic hydrocarbon group examples include a group in which two hydrogen atoms have been removed from the aforementioned aromatic hydrocarbon ring (arylene group); and a group in which one hydrogen atom has been removed from the aforementioned aromatic hydrocarbon ring (aryl group) and one hydrogen atom has been substituted with an alkylene group (such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group).
• the alkylene group (alkyl chain within the arylalkyl group) preferably has 1 to 4 carbon atom, more preferably 1 or 2, and most preferably 1.
• the hydrocarbon group for Wa 1 having a valency of n a2 +1 may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
• the aliphatic cyclic group refers to a hydrocarbon group that has no aromaticity, and may be either saturated or unsaturated, but is preferably saturated.
• Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure thereof, and a combination of the linear or branched aliphatic hydrocarbon group and the aliphatic hydrocarbon group containing a ring in the structure thereof.
• n a2 +1 is preferably divalent, trivalent or tetravalent, and divalent or trivalent is more preferable.
• R ⁇ represents a hydrogen atom, a methyl group or a trifluoromethyl group.
• a structural unit represented by the aforementioned general formula (a1-1) is preferable, and a structural unit represented by general formula (a1-11) shown below is more preferable.
• R 11 represents a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms; and Ra 11 represents an acid dissociable group.
• R 11 represents a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms, and is the same as defined for R in the aforementioned formula (a1-1), preferably a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a fluorinated alkyl group of 1 to 5 carbon atoms, and more preferably a hydrogen atom or a methyl group in terms of industrial availability.
• Ra 11 represents an acid dissociable group, and examples thereof include groups which have been proposed as acid dissociable groups for the base resin of a conventional chemically amplified resist composition.
• Ra 11 is the same as defined for Ra 01 (acid dissociable group) in the aforementioned formula (a0-1), and examples thereof include “acetal-type acid dissociable group” and “tertiary alkyl ester-type acid dissociable group”.
• a tertiary alkyl ester-type acid dissociable group is preferable, and a group represented by the aforementioned formula (a1-r2-1) or a group represented by the aforementioned formula (a1-r2-4) is more preferable.
• a group represented by the aforementioned formula (a1-r2-1) is still more preferable.
• 1 type of structural unit may be used, or 2 or more types may be used.
• the amount of the structural unit (a1) based on the combined total of all structural units constituting the component (A1) (100 mol %) is preferably 1 to 30 mol %, more preferably 2 to 27.5 mol %, still more preferably 5 to 20 mol %, and still more preferably 5 to 15 mol %.
• the amount of the structural unit (a1) is at least as large as the lower limit of the above-mentioned range, a resist pattern can be reliably obtained, and various lithography properties such as sensitivity, resolution and roughness are further reduced.
• the amount of the structural unit (a1) is no more than the upper limit of the above-mentioned range, a good balance can be achieved with the other structural units.
• the component (A1) may include, in addition to the structural unit (a0), a structural unit (a2) containing a lactone-containing cyclic group, an —SO 2 — containing cyclic group or a carbonate-containing cyclic group.
• the lactone-containing cyclic group, the —SO 2 — containing cyclic group or the carbonate-containing cyclic group within the structural unit (a2) is effective in improving the adhesion between the resist film and the substrate. Further, by virtue of including the structural unit (a2), in an alkali developing process, during developing, the solubility of the resist film in an alkali developing is enhanced.
• lactone-containing cyclic group refers to a cyclic group including a ring containing a —O—C( ⁇ O)— structure (lactone ring).
• lactone ring refers to a single ring containing a —O—C(O)— structure, and this ring is counted as the first ring.
• a lactone-containing cyclic group in which the only ring structure is the lactone ring is referred to as a monocyclic group, and groups containing other ring structures are described as polycyclic groups regardless of the structure of the other rings.
• the lactone-containing cyclic group may be either a monocyclic group or a polycyclic group.
• the lactone-containing cyclic group for the structural unit (a2) is not particularly limited, and an arbitrary structural unit may be used. Specific examples include groups represented by general formulae (a2-r-1) to (a2-r-7) shown below.
• each Ra′ 21 independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxy group, —COOR′′, —OC( ⁇ O)R′′, a hydroxyalkyl group or a cyano group;
• R′′ represents a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group or an —SO 2 — containing cyclic group;
• A′′ represents an oxygen atom, a sulfur atom, or an alkylene group of 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom;
• n′ represents an integer of 0 to 2; and
• m′ represents 0 or 1.
• the alkyl group for Ra′ 21 is preferably an alkyl group of 1 to 6 carbon atoms.
• the alkyl group is preferably a linear alkyl group or a branched alkyl group. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group and a hexyl group. Among these, a methyl group or ethyl group is preferable, and a methyl group is most preferable.
• the alkoxy group for Ra′ 21 is preferably an alkoxy group of 1 to 6 carbon atoms.
• the alkoxy group is preferably a linear or branched alkoxy group.
• Specific examples of the alkoxy groups include the aforementioned alkyl groups for Ra′ 21 having an oxygen atom (—O—) bonded thereto.
• halogen atom for Ra′ 21 a fluorine atom, chlorine atom, bromine atom and iodine atom can be given. Among these, a fluorine atom is preferable.
• halogenated alkyl group for Ra′ 21 examples include groups in which part or all of the hydrogen atoms within the aforementioned alkyl group for Ra′ 21 has been substituted with the aforementioned halogen atoms.
• a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly desirable.
• R′′ represents a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group or an —SO 2 — containing cyclic group.
• the alkyl group for R′′ may be linear, branched or cyclic, and preferably has 1 to 15 carbon atoms.
• R′′ represents a linear or branched alkyl group, it is preferably an alkyl group of 1 to 10 carbon atoms, more preferably an alkyl group of 1 to 5 carbon atoms, and most preferably a methyl group or an ethyl group.
• R′′ is a cyclic alkyl group (cycloalkyl group), it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and still more preferably 5 to 10 carbon atoms.
• Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane such as a bicycloalkane, tricycloalkane or tetracycloalkane which may or may not be substituted with a fluorine atom or a fluorinated alkyl group.
• Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; and groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobomane, tricyclodecane or tetracyclododecane.
• lactone-containing cyclic group for R′′ examples include groups represented by the aforementioned general formulae (a2-r-1) to (a2-r-7).
• the carbonate-containing cyclic group for R′′ is the same as defined for the carbonate-containing cyclic group described later.
• Specific examples of the carbonate-containing cyclic group include groups represented by general formulae (ax3-r-1) to (ax3-r-3).
• the —SO 2 — containing cyclic group for R′′ is the same as defined for the —SO 2 -containing cyclic group described later.
• Specific examples of the —SO 2 — containing cyclic group include groups represented by general formulae (a5-r-1) to (a5-r-4).
• the hydroxyalkyl group for Ra′ 21 preferably has 1 to 6 carbon atoms, and specific examples thereof include the alkyl groups for Ra′ 21 in which at least one hydrogen atom has been substituted with a hydroxy group.
• alkylene group of 1 to 5 carbon atoms represented by A′′ a linear or branched alkylene group is preferable, and examples thereof include a methylene group, an ethylene group, an n-propylene group and an isopropylene group.
• alkylene groups that contain an oxygen atom or a sulfur atom include the aforementioned alkylene groups in which —O— or —S— is bonded to the terminal of the alkylene group or present between the carbon atoms of the alkylene group.
• alkylene groups include —O—CH 2 —, —CH 2 —O—CH 2 —, —S—CH 2 —, and —CH 2 —S—CH 2 —.
• A′′ an alkylene group of 1 to 5 carbon atoms or —O— is preferable, more preferably an alkylene group of 1 to 5 carbon atoms, and most preferably a methylene group.
• —SO 2 — containing cyclic group refers to a cyclic group having a ring containing —SO 2 — within the ring structure thereof, i.e., a cyclic group in which the sulfur atom (S) within —SO 2 — forms part of the ring skeleton of the cyclic group.
• the ring containing —SO 2 — within the ring skeleton thereof is counted as the first ring.
• a cyclic group in which the only ring structure is the ring that contains —SO 2 — in the ring skeleton thereof is referred to as a monocyclic group, and a group containing other ring structures is described as a polycyclic group regardless of the structure of the other rings.
• the —SO 2 — containing cyclic group may be either a monocyclic group or a polycyclic group.
• a cyclic group containing —O—SO 2 — within the ring skeleton thereof i.e., a cyclic group containing a sultone ring in which —O—S— within the —O—SO 2 — group forms part of the ring skeleton thereof is particularly desirable.
• —SO 2 — containing cyclic group examples include groups represented by general formulas (a5-r-1) to (a5-r-4) shown below.
• each Ra′ 51 independently represents an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, —COOR′′, —OC( ⁇ O)R′′, a hydroxyalkyl group or a cyano group;
• R′′ represents a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group or an —SO 2 — containing cyclic group;
• A′′ represents an oxygen atom, a sulfur atom, or an alkylene group of 1 to 5 carbon atoms with or without an oxygen atom or a sulfur atom; and
• n′ represents an integer of 0 to 2.
• A′′ is the same as defined for A′′ in general formulae (a2-r-2), (a2-r-3) and (a2-r-5).
• Examples of the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, —COOR′′, —OC( ⁇ O)R′′ and hydroxyalkyl group for Ra′ 51 include the same groups as those described above in the explanation of Ra′ 21 in the general formulas (a2-r-1) to (a2-r-7).
• carbonate-containing cyclic group refers to a cyclic group including a ring containing a —O—C( ⁇ O)—O— structure (carbonate ring).
• carbonate ring refers to a single ring containing a —O—C( ⁇ O)—O— structure, and this ring is counted as the first ring.
• a carbonate-containing cyclic group in which the only ring structure is the carbonate ring is referred to as a monocyclic group, and groups containing other ring structures are described as polycyclic groups regardless of the structure of the other rings.
• the carbonate-containing cyclic group may be either a monocyclic group or a polycyclic group.
• the carbonate-containing cyclic group is not particularly limited, and an arbitrary group may be used. Specific examples include groups represented by general formulae (ax3-r-1) to (ax3-r-3) shown below.
• each Ra′ x31 independently represents an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, —COOR′′, —OC( ⁇ O)R′′, a hydroxyalkyl group or a cyano group;
• R′′ represents a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group or an —SO 2 — containing cyclic group;
• A′′ represents an oxygen atom, a sulfur atom, or an alkylene group of 1 to 5 carbon atoms with or without an oxygen atom or a sulfur atom;
• p′ represents an integer of 0 to 3; and q′ is 0 or 1.
• A′′ is the same as defined for A′′ in general formulae (a2-r-2), (a2-r-3) and (a2-r-5).
• Examples of the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, —COOR′′, —OC( ⁇ O)R′′ and hydroxyalkyl group for Ra′ 31 include the same groups as those described above in the explanation of Ra′ 21 in the general formulas (a2-r-1) to (a2-r-7).
• the structural unit (a2) a structural unit derived from an acrylate ester which may have the hydrogen atom bonded to the carbon atom on the ⁇ -position substituted with a substituent is preferable.
• preferable structural units for the structural unit (a2) include structural units represented by general formula (a2-1) shown below.
• R represents a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms
• Ya 21 represents a single bond or a divalent linking group
• La 21 represents —O—, —COO—, —CON(R′)—, —OCO—, —CONHCO— or —CONHCS—
• R′ represents a hydrogen atom or a methyl group
• R is the same as defined above.
• R a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a fluorinated alkyl group of 1 to 5 carbon atoms is preferable, and a hydrogen atom or a methyl group is particularly desirable in terms of industrial availability.
• the divalent linking group for Ya 21 is not particularly limited, and preferable examples thereof include a divalent hydrocarbon group which may have a substituent and a divalent linking group containing a hetero atom.
• the divalent hydrocarbon group for Ya 21 is the same as defined for the divalent hydrocarbon group represented by Va 1 in the aforementioned formula (a1-1).
• Examples of the substituent for the divalent hydrocarbon group represented by Ya 21 include an alkyl group of 1 to 5 carbon atoms, an alkoxy group, a halogen atom, a halogenated alkyl group of 1 to 5 carbon atoms, a hydroxy group, a carbonyl group.
• Ya 21 represents a divalent linking group containing a hetero atom
• the linking group include —O—, —C( ⁇ O)—O—, —C( ⁇ O)—, —O—C( ⁇ O)—O—, —C( ⁇ O)—NH—, —NH—, —NH—C( ⁇ NH)— (may be substituted with a substituent such as an alkyl group, an acyl group or the like), —S—, —S( ⁇ O) 2 —, —S( ⁇ O) 2 —O—, and a group represented by general formula: —Y 21 —O—Y 22 —, —Y 21 —O—, —Y 21 —C( ⁇ O)—O—, —C( ⁇ O)—O—Y 21 —, [Y 21 —C( ⁇ O)—O] m —Y 22 —, —Y 21 —O—C( ⁇ O)—Y 22 — or —Y 21
• H may be substituted with a substituent such as an alkyl group, an acyl group or the like.
• the substituent an alkyl group, an acyl group or the like
• the divalent hydrocarbon group include the same groups as those described above as the “divalent hydrocarbon group which may have a substituent” in the explanation of the aforementioned divalent linking group.
• a linear aliphatic hydrocarbon group is preferable, more preferably a linear alkylene group, still more preferably a linear alkylene group of 1 to 5 carbon atoms, and a methylene group or an ethylene group is particularly desirable.
• a linear or branched aliphatic hydrocarbon group is preferable, and a methylene group, an ethylene group or an alkylmethylene group is more preferable.
• the alkyl group within the alkylmethylene group is preferably a linear alkyl group of 1 to 5 carbon atoms, more preferably a linear alkyl group of 1 to 3 carbon atoms, and most preferably a methyl group.
• m′′ represents an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 1.
• the group represented by the formula —[Y 21 —C( ⁇ O)—O] m ′′-Y 22 — is a group represented by the formula —Y 21 —C( ⁇ O)—O—Y 22 —.
• a group represented by the formula —(CH 2 ) a′ —C( ⁇ O)—O—(CH 2 ) b′ — is preferable.
• a′ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1.
• b′ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1.
• Ya 21 preferably represents an ester bond [—C( ⁇ O)—O—], an ether bond (—O—), a linear or branched alkylene group, a combination of these, or a single bond.
• La 21 represents —O—, —COO—, —CON(R′)—, —OCO—, —CONHCO— or —CONHCS—.
• R′ represents a hydrogen atom or a methyl group.
• Ra 21 represents a lactone-containing cyclic group, an —SO 2 — containing cyclic group or a carbonate-containing cyclic group.
• lactone-containing cyclic group, the —SO 02 -containing cyclic group and the carbonate-containing cyclic group for Ra 21 include groups represented by general formulae (a2-r-1) to (a2-r-7), groups represented by general formulae (a5-r-1) to (a5-r-4) and groups represented by general formulae (ax3-r-1) to (ax3-r-3).
• Ra 21 a lactone-containing cyclic group or an —SO 2 — containing cyclic group is preferable, and a group represented by the aforementioned general formula (a2-r-1), (a2-r-2), (a2-r-6) or (a5-r-1) is more preferable. Specifically, a group represented by any of chemical formulae (r-1c-1-1) to (r-1c-1-7), (r-1c-2-1) to (r-1c-2-19), (r-1c-6-1), (r-s1-1-1) and (r-s1-1-18) is still more preferable.
• Ra 21 a lactone-containing cyclic group is preferable, and a group represented by any one of the aforementioned chemical formulae (r-1c-2-1) to (r-1c-2-19) is more preferable.
• structural unit (a2) contained in the component (A1) 1 kind of structural unit may be used, or 2 or more kinds may be used.
• the amount of the structural unit (a2) based on the combined total (100 mol %) of all structural units constituting the component (A1) is preferably 5 to 70 mol %, more preferably 10 to 65 mol %, still more preferably 20 to 60 mol %, and still more preferably 30 to 55 mol %.
• the amount of the structural unit (a2) is at least as large as the lower limit of the above preferable range, the effect of using the structural unit (a2) may be satisfactorily achieved.
• the amount of the structural unit (a2) is no more than the upper limit of the above preferable range, a good balance can be achieved with the other structural units, and various lithography properties and pattern shape may be improved.
• the component (A1) may include, in addition to the structural unit (a0), a structural unit (a3) containing a polar group-containing aliphatic hydrocarbon group (provided that the structural units that fall under the definition of structural units (a0), (a1) and (a2) are excluded).
• the hydrophilicity of the component (A1) is enhanced, thereby contributing to improvement in resolution.
• Examples of the polar group include a hydroxyl group, cyano group, carboxyl group, or hydroxyalkyl group in which part of the hydrogen atoms of the alkyl group have been substituted with fluorine atoms, although a hydroxyl group is particularly desirable.
• aliphatic hydrocarbon group examples include linear or branched hydrocarbon groups (preferably alkylene groups) of 1 to 10 carbon atoms, and cyclic aliphatic hydrocarbon groups (cyclic groups). These cyclic groups can be selected appropriately from the multitude of groups that have been proposed for the resins of resist compositions designed for use with ArF excimer lasers.
• the cyclic group is preferably a polycyclic group, more preferably a polycyclic group of 7 to 30 carbon atoms.
• structural units derived from an acrylate ester that include an aliphatic polycyclic group that contains a hydroxyl group, cyano group, carboxyl group or a hydroxyalkyl group in which part of the hydrogen atoms of the alkyl group have been substituted with fluorine atoms are particularly desirable.
• the polycyclic group include groups in which two or more hydrogen atoms have been removed from a bicycloalkane, tricycloalkane, tetracycloalkane or the like.
• groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobomane, tricyclodecane or tetracyclododecane.
• adamantane norbornane
• isobomane tricyclodecane or tetracyclododecane.
• groups in which two or more hydrogen atoms have been removed from adamantane, norbornane or tetracyclododecane are preferred industrially.
• the structural unit (a3) there is no particular limitation as long as it is a structural unit containing a polar group-containing aliphatic hydrocarbon group, and an arbitrary structural unit may be used.
• the structural unit (a3) is preferably a structural unit derived from an acrylate ester which may have the hydrogen atom bonded to the carbon atom on the ⁇ -position substituted with a substituent and contains a polar group-containing aliphatic hydrocarbon group.
• the structural unit (a3) is preferably a structural unit derived from a hydroxyethyl ester of acrylic acid.
• the hydrocarbon group is a polycyclic group, structural units represented by formulas (a3-1), (a3-2) and (a3-3) shown below are preferable.
• R is the same as defined above; j is an integer of 1 to 3; k is an integer of 1 to 3; t′ is an integer of 1 to 3; 1 is an integer of 1 to 5; and s is an integer of 1 to 3.
• j is preferably 1 or 2, and more preferably 1.
• j is 2, it is preferable that the hydroxyl groups be bonded to the 3rd and 5th positions of the adamantyl group.
• j is 1, it is preferable that the hydroxyl group be bonded to the 3rd position of the adamantyl group.
• j is preferably 1, and it is particularly desirable that the hydroxyl group be bonded to the 3rd position of the adamantyl group.
• k is preferably 1.
• the cyano group is preferably bonded to the 5th or 6th position of the norbomyl group.
• t′ is preferably 1.
• l is preferably 1.
• s is preferably 1.
• a 2-norbomyl group or 3-norbomyl group be bonded to the terminal of the carboxy group of the acrylic acid.
• the fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbomyl group.
• structural unit (a3) contained in the component (A1) 1 kind of structural unit may be used, or 2 or more kinds of structural units may be used.
• the amount of the structural unit (a3) based on the combined total (100 mol %) of all structural units constituting the component (A1) is preferably 1 to 50 mol %, more preferably 3 to 40 mol %, still more preferably 5 to 30 mol %, and most preferably 10 to 30 mol %.
• the amount of the structural unit (a3) is at least as large as the lower limit of the above-mentioned preferable range, the resolution is improved in the formation of a resist pattern.
• the amount of the structural unit (a3) is no more than the upper limit of the above-mentioned preferable range, a good balance can be reliably achieved with the other structural units.
• the component (A1) may be further include, in addition to the structural unit (a0), a structural unit (a4) containing an acid non-dissociable, aliphatic cyclic group.
• the component (A1) includes the structural unit (a4)
• dry etching resistance of the resist pattern to be formed is improved.
• the hydrophobicity of the component (A) is further improved. Increase in the hydrophobicity contributes to improvement in terms of resolution, shape of the resist pattern and the like, particularly in a solvent developing process.
• an “acid non-dissociable, aliphatic cyclic group” in the structural unit (a4) refers to a cyclic group which is not dissociated by the action of the acid (e.g., acid generated from a structural unit which generates acid upon exposure or acid generated from the component (B)) upon exposure, and remains in the structural unit.
• the structural unit (a4) a structural unit which contains a non-acid-dissociable aliphatic cyclic group, and is also derived from an acrylate ester is preferable.
• the cyclic group any of the multitude of conventional polycyclic groups used within the resin component of resist compositions for ArF excimer lasers or KrF excimer lasers (and particularly for ArF excimer lasers) can be used.
• At least one polycyclic group selected from amongst a tricyclodecyl group, adamantyl group, tetracyclododecyl group, isobornyl group, and norbornyl group is particularly desirable in consideration of industrial availability and the like.
• These polycyclic groups may be substituted with a linear or branched alkyl group of 1 to 5 carbon atoms.
• structural unit (a4) include structural units represented by general formulae (a4-1) to (a4-7) shown below.
• R ⁇ is the same as defined above.
• 1 type of structural unit may be used, or 2 or more types may be used.
• the amount of the structural unit (a4) based on the combined total (100 mol %) of all structural units constituting the component (A1) is preferably 1 to 40 mol %, and more preferably 5 to 20 mol %.
• the amount of the structural unit (a4) is at least as large as the lower limit of the above-mentioned preferable range, the effect of using the structural unit (a4) can be satisfactorily achieved.
• the amount of the structural unit (a4) is no more than the upper limit of the above-mentioned preferable range, a good balance can be achieved with the other structural units.
• the structural unit (a10) is a structural unit represented by general formula (a10-1) shown below.
• R represents a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms
• Ya x1 represents a single bond or a divalent linking group
• Wa x1 represents an aromatic hydrocarbon group having a valency of (n ax1 +1); and n ax1 represents an integer of 1 or more.
• R represents a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms.
• alkyl group having 1 to 5 carbon atoms for R a linear or branched alkyl group of 1 to 5 carbon atoms is preferable, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group and a neopentyl group.
• the halogenated alkyl group of 1 to 5 carbon atoms represented by R is a group in which part or all of the hydrogen atoms of the aforementioned alkyl group of 1 to 5 carbon atoms have been substituted with halogen atoms.
• the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is particularly desirable.
• a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a fluorinated alkyl group of 1 to 5 carbon atoms is preferable, and in view of industrial availability, a hydrogen atom, a methyl group or a trifluoromethyl group is more preferable, a hydrogen atom or a methyl group is still more preferable, and a methyl group is most preferable.
• Ya x1 represents a single bond or a divalent linking group.
• the divalent linking group for Ya x1 is not particularly limited, and preferable examples thereof include a divalent hydrocarbon group which may have a substituent and a divalent linking group containing a hetero atom.
• the hydrocarbon group may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
• aliphatic hydrocarbon group refers to a hydrocarbon group that has no aromaticity.
• the aliphatic hydrocarbon group may be saturated or unsaturated. In general, the aliphatic hydrocarbon group is preferably saturated.
• Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group containing a ring in the structure thereof can be given.
• the linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, still more preferably 1 to 4, and most preferably 1 to 3.
• a linear alkylene group is preferable. Specific examples thereof include a methylene group [—CH 2 —], an ethylene group [—(CH 2 ) 2 —], a trimethylene group [—(CH 2 ) 3 —], a tetramethylene group [—(CH 2 ) 4 -] and a pentamethylene group [—(CH 2 ) 5 —].
• the branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6, still more preferably 3 or 4, and most preferably 3.
• branched alkylene groups are preferred, and specific examples include various alkylalkylene groups, including alkylmethylene groups such as —CH(CH 3 )—, —CH(CH 2 CH 3 )—, —C(CH 3 ) 2 —, —C(CH 3 )(CH 2 CH 3 )—, —C(CH 3 )(CH 2 CH 2 CH 3 )—, and —C(CH 2 CH 3 ) 2 —; alkylethylene groups such as —CH(CH 3 )CH 2 —, —CH(CH 3 )CH(CH 3 )—, —C(CH 3 ) 2 CH 2 —, —CH(CH 2 CH 3 )CH 2 —, and —C(CH 2 CH 3 ) 2 —CH 2 —; alkyltrimethylene groups such as —CH(CH 3 )CH 2 CH 2 —, and —CH 2 CH(CH 3 )CH 2 —; and
• the linear or branched aliphatic hydrocarbon group may or may not have a substituent.
• substituents include a fluorine atom, a fluorinated alkyl group of 1 to 5 carbon atoms, and a carbonyl group.
• a cyclic aliphatic hydrocarbon group containing a hetero atom in the ring structure thereof and may have a substituent a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring
• a group in which the cyclic aliphatic hydrocarbon group is bonded to the terminal of the aforementioned chain-like aliphatic hydrocarbon group, and a group in which the cyclic aliphatic group is interposed within the aforementioned linear or branched aliphatic hydrocarbon group can be given.
• the linear or branched aliphatic hydrocarbon group the same groups as those described above can be used.
• the cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
• the cyclic aliphatic hydrocarbon group may be either a polycyclic group or a monocyclic group.
• the monocyclic aliphatic hydrocarbon group a group in which 2 hydrogen atoms have been removed from a monocycloalkane is preferable.
• the monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane.
• the polycyclic group a group in which 2 hydrogen atoms have been removed from a polycycloalkane is preferable, and the polycyclic group preferably has 7 to 12 carbon atoms. Examples of the polycycloalkane include adamantane, norbornane, isobomane, tricyclodecane and tetracyclododecane.
• the cyclic aliphatic hydrocarbon group may or may not have a substituent.
• substituents include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group and a carbonyl group.
• the alkyl group as the substituent is preferably an alkyl group of 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group.
• the alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group or tert-butoxy group, and still more preferably a methoxy group or an ethoxy group.
• halogen atom for the substituent examples include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferable.
• halogenated alkyl group for the substituent examples include groups in which part or all of the hydrogen atoms within the aforementioned alkyl groups has been substituted with the aforementioned halogen atoms.
• the cyclic aliphatic hydrocarbon group may have part of the carbon atoms constituting the ring structure thereof substituted with a substituent containing a hetero atom.
• a substituent containing a hetero atom —O—, —C( ⁇ O)—O—, —S—, —S( ⁇ O) 2 — or —S( ⁇ O) 2 —O— is preferable.
• the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.
• the aromatic ring is not particularly limited, as long as it is a cyclic conjugated compound having (4n+2) ⁇ electrons, and may be either monocyclic or polycyclic.
• the aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, and still more preferably 6 to 15 carbon atoms, and most preferably 6 to 12 carbon atoms.
• the number of carbon atoms within a substituent(s) is not included in the number of carbon atoms of the aromatic hydrocarbon group.
• aromatic ring examples include aromatic hydrocarbon rings, such as benzene, naphthalene, anthracene and phenanthrene; and aromatic hetero rings in which part of the carbon atoms constituting the aforementioned aromatic hydrocarbon rings has been substituted with a hetero atom.
• hetero atom within the aromatic hetero rings include an oxygen atom, a sulfur atom and a nitrogen atom.
• aromatic hetero ring include a pyridine ring and a thiophene ring.
• aromatic hydrocarbon group examples include a group in which two hydrogen atoms have been removed from the aforementioned aromatic hydrocarbon ring or aromatic hetero ring (arylene group or heteroarylene group); a group in which two hydrogen atoms have been removed from an aromatic compound having two or more aromatic rings (biphenyl, fluorene or the like); and a group in which one hydrogen atom of the aforementioned aromatic hydrocarbon ring or aromatic hetero ring has been substituted with an alkylene group (a group in which one hydrogen atom has been removed from the aryl group within the aforementioned arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group, or a heteroarylalkyl group).
• the hydrogen atom within the aromatic hydrocarbon group may be substituted with a substituent.
• the hydrogen atom bonded to the aromatic ring within the aromatic hydrocarbon group may be substituted with a substituent.
• substituents include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group.
• the alkyl group as the substituent is preferably an alkyl group of 1 to 5 carbon atoms, and more preferably a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group.
• the same groups as the aforementioned substituent groups for substituting a hydrogen atom within the cyclic aliphatic hydrocarbon group can be used.
• Ya x1 represents a divalent linking group containing a hetero atom
• the linking group include —O—, —C( ⁇ O)—O—, —O—C( ⁇ O)—, —C( ⁇ O)—, —O—C( ⁇ O)—O—, —C( ⁇ O)—NH—, —NH—, —NH—C( ⁇ NH)— (may be substituted with a substituent such as an alkyl group, an acyl group or the like), —S—, —S( ⁇ O) 2 —, —S( ⁇ O) 2 —O—, and a group represented by general formula: —Y 21 —O—Y 22 —, —Y 21 —O—, —Y 21 —C( ⁇ O)—O—, —C( ⁇ O)—O—Y 21 —, —[Y 21 —C( ⁇ O)—O] m′ —Y 22 —, —Y 21 —O
• H may be substituted with a substituent such as an alkyl group, an acyl group or the like.
• the substituent an alkyl group, an acyl group or the like
• the divalent hydrocarbon group include the same groups as those described above as the “divalent hydrocarbon group which may have a substituent” in the explanation of the aforementioned divalent linking group for Ya x1 .
• a linear aliphatic hydrocarbon group is preferable, more preferably a linear alkylene group, still more preferably a linear alkylene group of 1 to 5 carbon atoms, and a methylene group or an ethylene group is particularly desirable.
• a linear or branched aliphatic hydrocarbon group is preferable, and a methylene group, an ethylene group or an alkylmethylene group is more preferable.
• the alkyl group within the alkylmethylene group is preferably a linear alkyl group of 1 to 5 carbon atoms, more preferably a linear alkyl group of 1 to 3 carbon atoms, and most preferably a methyl group.
• m′′ represents an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 1.
• the group represented by the formula —[Y 21 —C( ⁇ O)—O] m′′ —Y 22 — is a group represented by the formula —Y 21 —C( ⁇ O)—O—Y 22 —.
• a group represented by the formula —(CH 2 ) a′ —C( ⁇ O)—O—(CH 2 ) b′ — is preferable.
• a′ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1.
• b′ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1.
• a single bond, an ester bond [—C( ⁇ O)—O—, —O—C( ⁇ O)—], an ether bond (—O—), a linear or branched alkylene group, or a combination of these is preferable, and a single bond or an ester bond [—C( ⁇ O)—O—, —O—C( ⁇ O)—] is more preferable.
• Wa x1 represents an aromatic hydrocarbon group having a valency of (n ax1 +1).
• Examples of the aromatic hydrocarbon group for Wa x1 include a group obtained by removing (n ax1 +1) hydrogen atoms from an aromatic ring.
• the aromatic ring is not particularly limited, as long as it is a cyclic conjugated compound having (4n+2) ⁇ electrons, and may be either monocyclic or polycyclic.
• the aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, and still more preferably 6 to 15 carbon atoms, and most preferably 6 to 12 carbon atoms.
• the aromatic ring examples include an aromatic hydrocarbon ring, such as benzene, naphthalene, anthracene or phenanthrene; and an aromatic heterocyclic ring in which part of the carbon atoms constituting the aromatic hydrocarbon ring has been substituted with a hetero atom.
• the hetero atom within the aromatic hetero rings include an oxygen atom, a sulfur atom and a nitrogen atom.
• Specific examples of the aromatic hetero ring include a pyridine ring and a thiophene ring.
• aromatic hydrocarbon group for Wa x1 examples include a group in which (n ax1 +1) hydrogen atom(s) has been removed from an aromatic group containing 2 or more aromatic rings (e.g., biphenyl, fluorene, or the like).
• Wa x1 a group in which (n ax1 +1) hydrogen atoms have been removed from benzene, naphthalene, anthracene or biphenyl is preferable, a group in which (n ax1 +1) hydrogen atoms have been removed from benzene or naphthalene is more preferable, and a group in which (n ax1 +1) hydrogen atoms have been removed from benzene is still more preferable.
• n ax1 is an integer of 1 or more, preferably an integer of 1 to 10, more preferably an integer of 1 to 5, still more preferably 1, 2 or 3, and most preferably 1 or 2.
• R ⁇ represents a hydrogen atom, a methyl group or a trifluoromethyl group.
• 1 kind of structural unit may be used, or 2 or more kinds of structural units may be used.
• the amount of the structural unit (a10) based on the combined total of all structural units constituting the component (A1) (100 mol %) is preferably 5 to 50 mol %, more preferably 5 to 40 mol %, and still more preferably 10 to 30 mol %.
• the amount of the structural unit (a10) is at least as large as the lower limit of the above preferable range, the sensitivity may be more reliably enhanced.
• the amount of the structural unit (a10) is no more than the upper limit of the above-mentioned range, a good balance may be reliably achieved with the other structural units.
• Structural Unit Derived from Styrene or a Derivative Thereof Structural Unit (St)
• styrene is a concept including styrene and compounds in which the hydrogen atom at the ⁇ -position of styrene is substituted with a substituent such as an alkyl group or a halogenated alkyl group.
• a substituent such as an alkyl group or a halogenated alkyl group.
• alkyl group as the substituent include an alkyl group having 1 to 5 carbon atoms.
• halogenated alkyl group as the substituent include a halogenated alkyl group having 1 to 5 carbon atoms.
• styrene derivative examples include styrene which has a substituent other than a hydroxy group bonded to the benzene ring and may have the hydrogen atom on the ⁇ -position substituted with a substituent.
• the ⁇ -position (carbon atom on the ⁇ -position) refers to the carbon atom having the benzene ring bonded thereto, unless specified otherwise.
• a “structural unit derived from styrene” or “structural unit derived from a styrene derivative” refers to a structural unit that is formed by the cleavage of the ethylenic double bond of styrene or a styrene derivative.
• 1 kind of structural unit may be used, or 2 or more kinds of structural units may be used.
• the amount of the structural unit (st) based on the combined total of all structural units constituting the component (A1) (100 mol %) is preferably 1 to 30 mol %, and more preferably 3 to 20 mol %.
• the resin component (A1) contains a polymer having the structural unit (a0).
• the component (A1) 1 kind of the polymer may be used, or 2 or more kinds of the polymers may be used in combination.
• the polymer having a structural unit (a0) include a polymer containing a copolymer having a structural unit (a0), a structural unit (a2) and any other desired structural unit; and a polymer containing a copolymer having a structural unit (a0), a structural unit (a1) and any other desired structural unit.
• a copolymer include a copolymer consisting of a repeating structure of a structural unit (a0) and a structural unit (a2); and a copolymer consisting of a repeating structure of a structural unit (a0), a structural unit (a2) and a structural unit (a1).
• the component (A1) has a structural unit (a0) and a structural unit (a1)
• a structural unit (a1) in terms of the effects of the present embodiment, it is preferable to use a combination of a structural unit represented by general formula (a0-1) with a structural unit represented by general formula (a1-11).
• both Ra 01 in the aforementioned general formula (a0-1) and Ra 11 in the aforementioned general formula (a1-11) is acid dissociable group which is a cyclic aliphatic hydrocarbon group having a tertiary carbon atom bonded to the oxygen atom (—O—) in the formulae.
• the amount of the structural unit (a0) is preferably 50 mol % or more, and may be 100 mol %.
• the amount of the structural unit (a0) based on the 100 mol % total of the structural unit (a0) and the structural unit (a1) is preferably 50 mol % or more, more preferably 50 to 95 mol %, and still more preferably 60 to 90 mol %.
• component (A2) a base component which exhibits changed solubility in a developing solution under action of acid
• component (A2) a base component which exhibits changed solubility in a developing solution under action of acid
• component (A2) there is no particular limitation, and any of the multitude of conventional base resins used within chemically amplified resist compositions may be arbitrarily selected for use.
• component (A2) one kind of a polymer or a low molecular weight compound may be used, or a combination of two or more kinds may be used.
• the amount of the component (A1) based on the total weight of the component (A) is preferably 50% by weight or more, more preferably 75% by weight or more, still more preferably 90% by weight or more, and may be even 100% by weight.
• the amount of the component (A1) is at least as large as the lower limit of the above preferable range, sensitivity may be improved, and a resist pattern with improved lithography properties such as resolution and reduced roughness may be reliably formed.
• the amount of the component (A) may be appropriately adjusted depending on the thickness of the resist film to be formed, and the like.
• the component (B) is an acid generator component which generates acid upon exposure.
• the component (B) includes an acid generator (B1) represented by general formula (b1) shown below (hereafter, also is referred to as “component (B1)”).
• R b01 represents a cyclic hydrocarbon group of 3 to 20 carbon atoms which may have a substituent; L b01 represents —O—C( ⁇ O)— or —C( ⁇ O)—O—; Y b01 represents a divalent linking group or a single bond; V b01 represents a fluorinated alkylene group having 1 to 9 carbon atoms; R b02 represents a fluorine atom or a hydrogen atom; provided that the total number of fluorine atoms contained in V b01 and R b02 is 2 or 3; m represents an integer of 1 or more; and M m+ represents an m-valent organic cation.
• R b01 represents a cyclic hydrocarbon group of 3 to 20 carbon atoms which may have a substituent.
• the cyclic hydrocarbon group for R b01 may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.
• An “aliphatic hydrocarbon group” refers to a hydrocarbon group that has no aromaticity.
• the aliphatic hydrocarbon group may be either saturated or unsaturated, but in general, the aliphatic hydrocarbon group is preferably saturated.
• the aromatic hydrocarbon group for R b01 is a hydrocarbon group having an aromatic ring.
• the aromatic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and still more preferably 6 to 10 carbon atoms.
• the number of carbon atoms within a substituent(s) is not included in the number of carbon atoms of the aromatic hydrocarbon group.
• Examples of the aromatic ring contained in the aromatic hydrocarbon group for R b01 include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic hetero ring in which part of the carbon atoms constituting the aromatic ring has been substituted with a hetero atom.
• Examples of the hetero atom within the aromatic hetero rings include an oxygen atom, a sulfur atom and a nitrogen atom.
• aromatic hydrocarbon group for R b01 include a group in which 1 hydrogen atom has been removed from the aforementioned aromatic ring (an aryl group, such as a phenyl group or a naphthyl group), and a group in which 1 hydrogen atom of the aforementioned aromatic ring has been substituted with an alkylene group (an arylalkyl group, such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group).
• the alkylene group (alkyl chain within the arylalkyl group) preferably has 1 to 4 carbon atom, more preferably 1 or 2, and most preferably 1.
• Examples of the cyclic aliphatic hydrocarbon group for R b01 include aliphatic hydrocarbon groups containing a ring in the structure thereof.
• an alicyclic hydrocarbon group (a group in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), a group in which the alicyclic hydrocarbon group is bonded to the terminal of the aforementioned chain-like aliphatic hydrocarbon group, and a group in which the alicyclic group is interposed within the aforementioned linear or branched aliphatic hydrocarbon group, can be given.
• the alicyclic hydrocarbon group has 3 to 20 carbon atoms, and preferably 3 to 12 carbon atoms.
• the alicyclic hydrocarbon group may be either a polycyclic group or a monocyclic group.
• the monocyclic alicyclic hydrocarbon group a group in which one or more hydrogen atoms have been removed from a monocycloalkane is preferable.
• the monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane.
• the polycyclic alicyclic hydrocarbon group a group in which one or more hydrogen atoms have been removed from a polycycloalkane is preferable, and the polycyclic group preferably has 7 to 20 carbon atoms.
• a polycycloalkane having a bridged ring polycyclic skeleton such as adamantane, norbomane, isobomane, tricyclodecane or tetracyclodpdecane
• a polycycloalkane having a condensed ring polycyclic skeleton such as a cyclic group having a steroid skeleton
• a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane is preferable, a group in which one or more hydrogen atoms have been removed from a polycycloalkane is more preferable, an adamantyl group or a norbomyl group is still more preferable, and an adamantyl group is most preferable.
• the linear or branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms.
• a linear alkylene group is preferable. Specific examples thereof include a methylene group [—CH 2 —], an ethylene group [—(CH 2 ) 2 —], a trimethylene group [—(CH 2 ) 3 —], a tetramethylene group [—(CH 2 ) 4 -] and a pentamethylene group [—(CH 2 ) 5 —].
• branched alkylene groups are preferred, and specific examples include various alkylalkylene groups, including alkylmethylene groups such as —CH(CH 3 )—, —CH(CH 2 CH 3 )—, —C(CH 3 ) 2 —, —C(CH 3 )(CH 2 CH 3 )—, —C(CH 3 )(CH 2 CH 2 CH 3 )—, and —C(CH 2 CH 3 ) 2 —; alkylethylene groups such as —CH(CH 3 )CH 2 —, —CH(CH 3 )CH(CH 3 )—, —C(CH 3 ) 2 CH 2 —, —CH(CH 2 CH 3 )CH 2 —, and —C(CH 2 CH 3 ) 2 —CH 2 —; alkyltrimethylene groups such as —CH(CH 3 )CH 2 CH 2 —, and —CH 2 CH(CH 3 )CH 2 —; and
• the cyclic hydrocarbon group for R b01 may contain a hetero atom such as a heterocycle.
• a heterocycle such as a heterocycle.
• Specific examples include lactone-containing cyclic groups represented by the aforementioned general formulae (a2-r-1) to (a2-r-7), the —SO 2 — containing cyclic group represented by the aforementioned formulae (a5-r-1) to (a5-r-4), and other heterocyclic groups represented by chemical formulae (r-hr-1) to (r-hr-16) shown below.
• R b01 in terms of the effects of the present embodiment, a cyclic aliphatic hydrocarbon group is preferable, and a group in which 1 hydrogen atom has been removed form a polycycloalkane is more preferable.
• an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group or the like can be used as the substituent for the cyclic group for R b01 .
• the alkyl group as the substituent is preferably an alkyl group of 1 to 5 carbon atoms, and a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group is particularly desirable.
• the alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group or tert-butoxy group, and most preferably a methoxy group or an ethoxy group.
• halogen atom for the substituent examples include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferable.
• Example of the aforementioned halogenated alkyl group includes a group in which a part or all of the hydrogen atoms within an alkyl group of 1 to 5 carbon atoms (e.g., a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group) have been substituted with the aforementioned halogen atoms.
• an alkyl group of 1 to 5 carbon atoms e.g., a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group
• the carbonyl group as the substituent is a group that substitutes a methylene group (—CH 2 —) constituting the cyclic hydrocarbon group.
• L b01 represents —O—C( ⁇ O)— or —C( ⁇ O)—O—.
• Y b01 represents a divalent linking group or a single bond.
• Examples of the divalent linking group for Y b10 include an oxygen atom (an ether bond: —O—), an alkylene group, or a combination thereof.
• the alkylene group preferably has 1 to 30 carbon atoms, more preferably 1 to 10 carbon atoms, and still more preferably 1 to 5 carbon atoms.
• the aforementioned combination of an oxygen atom (an ether bond:—O—) with an alkylene group may further have a sulfonyl group (—SO 2 —) linked thereto.
• Y b01 an alkylene group or a single bond is preferable.
• V b01 represents a fluorinated alkyl group having 1 to 9 carbon atoms.
• the fluorinated alkylene group for V b01 has 1 to 9 carbon atoms, preferably 1 to 4 carbon atoms.
• R b02 represents a fluorine atom or a hydrogen atom. However, the total number of fluorine atoms contained in V b01 and R b02 is 2 or 3.
• anion moieties for the component (B1) are shown below. However, the anion moiety of the component (B1) is not limited to these specific examples.
• M m+ represents an organic cation having a valency of m.
• an onium cation is preferable, and a sulfonium cation or a iodonium cation is more preferable.
• m represents an integer of 1 or more.
• organic cations represented by general formulae (ca-1) to (ca-5) shown below may be given.
• R 201 to R 207 , R 211 and R 212 each independently represents an aryl group, an alkyl group or an alkenyl group, provided that two of R 201 to R 203 , R 206 and R 207 , or R 211 and R 212 may be mutually bonded to form a ring with the sulfur atom;
• R 208 and R 209 each independently represents a hydrogen atom or an alkyl group of 1 to 5 carbon atoms;
• R 210 represents an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or an —SO 2 -containing cyclic group which may have a substituent;
• L 201 represents —C( ⁇ O)— or —C( ⁇ O)—O—;
• Y 201 each independently represents an arylene group, an alkylene group or an alkenylene group;
• x represents 1 or 2; and
• W 201
• aryl group for R 201 to R 207 , R 211 and R 212 an unsubstituted aryl group of 6 to 20 carbon atoms can be mentioned, and a phenyl group or a naphthyl group is preferable.
• the alkyl group for R 201 to R 207 , R 211 and R 212 is preferably a chain-like or cyclic alkyl group having 1 to 30 carbon atoms.
• the alkenyl group for R 201 to R 207 , R 211 and R 212 preferably has 2 to 10 carbon atoms.
• R 201 to R 207 and R 210 to R 212 may have include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and groups represented by formulae (ca-r-1) to (ca-r-7) shown below.
• each R′ 201 independently represents a hydrogen atom, a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent.
• R′ 201 represents a hydrogen atom, a cyclic group which may have a substituent, a chain alkyl group which may have a substituent or a chain alkenyl group which may have a substituent.
• the cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be either an aromatic hydrocarbon group or an aliphatic hydrocarbon group.
• An “aliphatic hydrocarbon group” refers to a hydrocarbon group that has no aromaticity.
• the aliphatic hydrocarbon group may be either saturated or unsaturated, but in general, the aliphatic hydrocarbon group is preferably saturated.
• the aromatic hydrocarbon group for R′ 201 is a hydrocarbon group having an aromatic ring.
• the aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms.
• the number of carbon atoms within a substituent(s) is not included in the number of carbon atoms of the aromatic hydrocarbon group.
• Examples of the aromatic ring contained in the aromatic hydrocarbon group for R′ 201 include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic hetero ring in which part of the carbon atoms constituting the aromatic ring has been substituted with a hetero atom.
• hetero atom within the aromatic hetero rings examples include an oxygen atom, a sulfur atom and a nitrogen atom.
• aromatic hydrocarbon group for R′ 201 include a group in which 1 hydrogen atom has been removed from the aforementioned aromatic ring (an aryl group, such as a phenyl group or a naphthyl group), and a group in which 1 hydrogen atom of the aforementioned aromatic ring has been substituted with an alkylene group (an arylalkyl group, such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group).
• the alkylene group (alkyl chain within the arylalkyl group) preferably has 1 to 4 carbon atom, more preferably 1 or 2, and most preferably 1.
• Examples of the cyclic aliphatic hydrocarbon group for R′ 201 include aliphatic hydrocarbon groups containing a ring in the structure thereof.
• an alicyclic hydrocarbon group (a group in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), a group in which the alicyclic hydrocarbon group is bonded to the terminal of the aforementioned chain-like aliphatic hydrocarbon group, and a group in which the alicyclic group is interposed within the aforementioned linear or branched aliphatic hydrocarbon group, can be given.
• the alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
• the alicyclic hydrocarbon group may be either a polycyclic group or a monocyclic group.
• the monocyclic alicyclic hydrocarbon group a group in which one or more hydrogen atoms have been removed from a monocycloalkane is preferable.
• the monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane.
• the polycyclic alicyclic hydrocarbon group a group in which one or more hydrogen atoms have been removed from a polycycloalkane is preferable, and the polycyclic group preferably has 7 to 30 carbon atoms.
• a polycycloalkane having a bridged ring polycyclic skeleton such as adamantane, norbornane, isobomane, tricyclodecane or tetracyclodpdecane
• a polycycloalkane having a condensed ring polycyclic skeleton such as a cyclic group having a steroid skeleton
• cyclic aliphatic hydrocarbon group for R′ 201 a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane is preferable, a group in which one or more hydrogen atoms have been removed from a polycycloalkane is more preferable, an adamantyl group or a norbomyl group is still more preferable, and an adamantyl group is most preferable.
• the linear or branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms.
• a linear alkylene group is preferable. Specific examples thereof include a methylene group [—CH 2 —], an ethylene group [—(CH 2 ) 2 —], a trimethylene group [—(CH 2 ) 3 —], a tetramethylene group [—(CH 2 ) 4 -] and a pentamethylene group [—(CH 2 ) 5 —].
• branched alkylene groups are preferred, and specific examples include various alkylalkylene groups, including alkylmethylene groups such as —CH(CH 3 )—, —CH(CH 2 CH 3 )—, —C(CH 3 ) 2 —, —C(CH 3 )(CH 2 CH 3 )—, —C(CH 3 )(CH 2 CH 2 CH 3 )—, and —C(CH 2 CH 3 ) 2 —; alkylethylene groups such as —CH(CH 3 )CH 2 —, —CH(CH 3 )CH(CH 3 )—, —C(CH 3 ) 2 CH 2 —, —CH(CH 2 CH 3 )CH 2 —, and —C(CH 2 CH 3 ) 2 —CH 2 —; alkyltrimethylene groups such as —CH(CH 3 )CH 2 CH 2 —, and —CH 2 CH(CH 3 )CH 2 —; and
• the cyclic hydrocarbon group for R′ 201 may contain a hetero atom such as a heterocycle.
• a heterocycle such as a heterocycle.
• Specific examples include lactone-containing cyclic groups represented by the aforementioned general formulae (a2-r-1) to (a2-r-7), the —SO 2 — containing cyclic group represented by the aforementioned formulae (a5-r-1) to (a5-r-4), and other heterocyclic groups represented by the aforementioned chemical formulae (r-hr-1) to (r-hr-16).
• an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group or the like can be used as the substituent for the cyclic group for R′ 201 .
• the alkyl group as the substituent is preferably an alkyl group of 1 to 5 carbon atoms, and a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group is particularly desirable.
• the alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group or tert-butoxy group, and most preferably a methoxy group or an ethoxy group.
• halogen atom for the substituent examples include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferable.
• Example of the aforementioned halogenated alkyl group includes a group in which a part or all of the hydrogen atoms within an alkyl group of 1 to 5 carbon atoms (e.g., a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group) have been substituted with the aforementioned halogen atoms.
• an alkyl group of 1 to 5 carbon atoms e.g., a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group
• the carbonyl group as the substituent is a group that substitutes a methylene group (—CH 2 —) constituting the cyclic hydrocarbon group.
• the chain alkyl group for R′ 201 may be linear or branched.
• the linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and still more preferably 1 to 10 carbon atoms.
• Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, an isotridecyl group, a tetradecyl group, a pentadecyl group, a hexadecyl group, an isohexadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, an icosyl group, a henicosyl group
• the branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and still more preferably 3 to 10 carbon atoms.
• Specific examples include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group and a 4-methylpentyl group.
• the chain alkenyl group for R′ 201 may be linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, still more preferably 2 to 4 carbon atoms, and most preferably 3 carbon atoms.
• linear alkenyl groups include a vinyl group, a propenyl group (an allyl group) and a butynyl group.
• branched alkenyl groups include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group and a 2-methylpropenyl group.
• chain-like alkenyl group a linear alkenyl group is preferable, a vinyl group or a propenyl group is more preferable, and a vinyl group is most preferable.
• an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, a cyclic group for R′ 201 or the like may be used.
• the chain alkyl group which may have a substituent and the chain alkenyl group which may have a substituent for R′ 201 the same groups as those described above may be mentioned.
• the cyclic group which may have a substituent and chain alkyl group which may have a substituent the same groups as those described above for the acid dissociable group represented by the aforementioned formula (a1-r-2) may be also mentioned.
• R′ 201 a cyclic group which may have a substituent is preferable, and a cyclic hydrocarbon group which may have a substituent is more preferable.
• a phenyl group, a naphthyl group, a group in which one or more hydrogen atoms have been removed from a polycycloalkane, a lactone-containing cyclic group represented by any one of the aforementioned formula (a2-r-1) to (a2-r-7), and an —SO 2 — containing cyclic group represented by any one of the aforementioned formula (a5-r-1) to (a5-r-4) are preferable.
• R 201 to R 203 , R 206 , R 207 , R 211 and R 212 are mutually bonded to form a ring with the sulfur atom
• these groups may be mutually bonded via a hetero atom such as a sulfur atom, an oxygen atom or a nitrogen atom, or a functional group such as a carbonyl group, —SO—, —SO 2 —, —SO 3 —, —COO—, —CONH— or —N(R N )— (wherein R N represents an alkyl group of 1 to 5 carbon atoms).
• the ring containing the sulfur atom in the skeleton thereof is preferably a 3 to 10-membered ring, and most preferably a 5 to 7-membered ring.
• Specific examples of the ring formed include a thiophene ring, a thiazole ring, a benzothiophene ring, a thianthrene ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a phenoxathiin ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.
• R 208 and R 209 each independently represents a hydrogen atom or an alkyl group of 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group of 1 to 3 carbon atoms, and when R 208 and R 209 each represents an alkyl group, R 208 and R 209 may be mutually bonded to form a ring.
• R 210 represents an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or an —SO 2 — containing cyclic group which may have a substituent.
• Examples of the aryl group for R 210 include an unsubstituted aryl group of 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferable.
• alkyl group for R 210 a chain-like or cyclic alkyl group having 1 to 30 carbon atoms is preferable.
• the alkenyl group for R 210 preferably has 2 to 10 carbon atoms.
• the —SO 2 — containing cyclic group for R 210 which may have a substituent is the same as defined for the —SO 2 — containing cyclic group represented by any of the aforementioned general formulae (a5-r-1) to (a5-r-4).
• the “—SO 2 — containing polycyclic group” is preferable, and a group represented by general formula (a5-r-1) is more preferable.
• each Y 201 independently represents an arylene group, an alkylene group or an alkenylene group.
• Examples of the arylene group for Y 201 include groups in which one hydrogen atom has been removed from an aryl group given as an example of the aromatic hydrocarbon group for R′ 201 .
• Examples of the alkylene group and alkenylene group for Y 201 include groups in which one hydrogen atom has been removed from the chain alkyl group or the chain alkenyl group given as an example of R′ 201 .
• W 201 represents a linking group having a valency of (x+1), i.e., a divalent or trivalent linking group.
• the divalent linking group for W 201 a divalent hydrocarbon group which may have a substituent is preferable, and as examples thereof, the same hydrocarbon groups (which may have a substituent) as those described above for Ya 21 in the general formula (a2-1) can be mentioned.
• the divalent linking group for W 201 may be linear, branched or cyclic, and cyclic is more preferable.
• an arylene group having two carbonyl groups, each bonded to the terminal thereof is preferable.
• the arylene group include a phenylene group and a naphthylene group, and a phenylene group is particularly desirable.
• the trivalent linking group for W 201 a group in which one hydrogen atom has been removed from the aforementioned divalent linking group for W 201 and a group in which the divalent linking group has been bonded to another divalent linking group can be mentioned.
• the trivalent linking group for W 201 is preferably a group in which 2 carbonyl groups are bonded to an arylene group.
• preferable cations represented by formula (ca-1) include cations represented by formulae (ca-1-1) to (ca-1-127) shown below.
• g1, g2 and g3 represent recurring numbers, wherein g1 is an integer of 1 to 5, g2 is an integer of 0 to 20, and g3 is an integer of 0 to 20.
• R′′ 201 represents a hydrogen atom or a substituent, and as the substituent, the same groups as those described above for substituting R 201 to R 207 and R 210 to R 212 can be mentioned.
• preferable cations represented by the formula (ca-2) include a dihphenyliodonium cation and a bis(4-tert-butylphenyl)iodonium cation.
• preferable cations represented by formula (ca-3) include cations represented by formulae (ca-3-1) to (ca-3-6) shown below.
• preferable cations represented by formula (ca-4) include cations represented by formulae (ca-4-1) and (ca-4-2) shown below.
• examples of preferable cations represented by formula (ca-5) include cations represented by formulae (ca-5-1) to (ca-5-3) shown below.
• a cation represented by general formula (ca-1) is preferable, and a cation represented by any one of formulae (ca-1-1) to (ca-1-127) is more preferable.
• the component (B1) one kind of compound may be used, or two or more kinds of compounds may be used in combination.
• the amount of the component (B1) relative to 100 parts by weight of the component (A) is preferably within a range from 2 to 20 parts by weight, more preferably from 5 to 15 parts by weight, and still more preferably from 5 to 10 parts by weight.
• the amount of the component (B1) is at least as large as the lower limit of the above-mentioned preferable range, in the formation of a resist pattern, various lithography properties such as line width roughness (LWR), dimension uniformity and pattern shape are improved.
• LWR line width roughness
• the amount of the component (B1) is no more than the upper limit of the above-mentioned range, when each of the components are dissolved in an organic solvent, a homogeneous solution may be more reliably obtained and the storage stability of the resist composition is improved.
• the resist composition of the present embodiment may contain an acid generator other than the component (B1) (hereafter, referred to as “component (B2)”), as long as the effects of the present invention are not impaired.
• component (B2) there is no particular limitation, and any of the known acid generators used in conventional chemically amplified resist compositions may be used.
• Examples of these acid generators are numerous, and include onium salt acid generators such as iodonium salts and sulfonium salts; oxime sulfonate acid generators; diazomethane acid generators such as bisalkyl or bisaryl sulfonyl diazomethanes and poly(bis-sulfonyl)diazomethanes; nitrobenzylsulfonate acid generators; iminosulfonate acid generators; and disulfone acid generators.
• onium salt acid generators such as iodonium salts and sulfonium salts
• oxime sulfonate acid generators diazomethane acid generators such as bisalkyl or bisaryl sulfonyl diazomethanes and poly(bis-sulfonyl)diazomethanes
• nitrobenzylsulfonate acid generators iminosulfonate acid generators
• component (b-1) As the onium salt acid generator, a compound represented by general formula (b-1) below (hereafter, sometimes referred to as “component (b-1)”), a compound represented by general formula (b-2) below (hereafter, sometimes referred to as “component (b-2)”) or a compound represented by general formula (b-3) below (hereafter, sometimes referred to as “component (b-3)”) may be mentioned.
• component (b-1) does not include compounds which fall under the category of the component (B1).
• R 101 and R 104 to R 108 each independently represents a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent or a chain-like alkenyl group which may have a substituent, provided that R 104 and R 105 may be mutually bonded to form a ring;
• R 102 represents a fluorine atom or a fluorinated alkyl group of 1 to 5 carbon atoms;
• Y 101 represents a single bond or a divalent linking group containing an oxygen atom;
• V 101 to V 103 each independently represents a single bond, an alkylene group or a fluorinated alkylene group;
• L 101 and L 102 each independently represents a single bond or an oxygen atom;
• L 103 to L 105 each independently represents a single bond, —CO— or —SO 2 —;
• m represents an integer of 1 or more; and
• M′ m+ represents an m-valent onium cation.
• R 101 represents a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent or a chain-like alkenyl group which may have a substituent.
• R 101 is the same as defined for the cyclic group which may have a substituent, the chain alkyl group which may have a substituent and the chain alkenyl group which may have a substituent for R′ 201 in the aforementioned formulae (ca-r-1) to (ca-r-7).
• Y 101 represents a single bond or a divalent linking group containing an oxygen atom.
• Y 101 may contain an atom other than an oxygen atom.
• atoms other than an oxygen atom include a carbon atom, a hydrogen atom, a sulfur atom and a nitrogen atom.
• divalent linking group containing an oxygen atom examples include divalent linking groups represented by general formula (y-a1-1) to (y-a1-7) shown below.
• V′ 101 represents a single bond or an alkylene group of 1 to 5 carbon atoms
• V′ 102 represents a divalent saturated hydrocarbon group of 1 to 30 carbon atoms.
• the divalent saturated hydrocarbon group for V′ 102 is preferably an alkylene group of 1 to 30 carbon atoms, more preferably an alkylene group of 1 to 10 carbon atoms, and still more preferably an alkylene group of 1 to 5 carbon atoms.
• the alkylene group for V′ 101 and V′ 102 may be a linear alkylene group or a branched alkylene group, and a linear alkylene group is preferable.
• alkylene group for V′ 101 and V′ 102 include a methylene group [—CH 2 —]; an alkylmethylene group, such as —CH(CH 3 )—, —CH(CH 2 CH 3 )—, —C(CH 3 ) 2 —, —C(CH 3 )(CH 2 CH 3 )—, —C(CH 3 )(CH 2 CH 2 CH 3 )— and —C(CH 2 CH 3 ) 2 —; an ethylene group [—CH 2 CH 2 —]; an alkylethylene group, such as —CH(CH 3 )CH 2 —, —CH(CH 3 )CH(CH 3 )—, —C(CH 3 ) 2 CH 2 — and —CH(CH 2 CH 3 )CH 2 —; a trimethylene group (n-propylene group) [—CH 2 CH 2 CH 2 —]; an alkyltrimethylene group, such as —CH(CH 3 )CH 2 CH 2
• part of methylene group within the alkylene group for V′ 101 and V′ 102 may be substituted with a divalent aliphatic cyclic group of 5 to 10 carbon atoms.
• the aliphatic cyclic group is preferably a divalent group in which one hydrogen atom has been removed from the cyclic aliphatic hydrocarbon group (monocyclic alicyclic hydrocarbon group or polycyclic alicyclic hydrocarbon group) for R 101 in the aforementioned formula (b-1), and a cyclohexylene group, 1,5-adamantylene group or 2,6-adamantylene group is preferable.
• Y 101 is preferably a divalent linking group containing an ether bond or a divalent linking group containing an ester bond, and groups represented by the aforementioned formulas (y-a1-1) to (y-a1-5) are preferable.
• V 101 represents a single bond, an alkylene group or a fluorinated alkylene group.
• the alkylene group and the fluorinated alkylene group for V 101 preferably has 1 to 4 carbon atoms.
• the fluorinated alkylene group for V 101 include a group in which part or all of the hydrogen atoms within the alkylene group for V 101 have been substituted with fluorine.
• V 101 a single bond or a fluorinated alkylene group of 1 to 4 carbon atoms is preferable.
• R 102 represents a fluorine atom or a fluorinated alkyl group of 1 to 5 carbon atoms.
• R 102 is preferably a fluorine atom or a perfluoroalkyl group of 1 to 5 carbon atoms, and more preferably a fluorine atom.
• anion moiety of the component (b-1) in the case where Y 101 represents a single bond, examples thereof include fluorinated alkylsulfonate anions such as a trifluoromethanesulfonate anion and perfluorobutanesulfonate.
• R 104 and R 105 each independently represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent or a chain alkenyl group which may have a substituent, and is the same as defined for R′ 201 , R 104 and R 105 may be mutually bonded to form a ring.
• R 104 and R 105 a chain-like alkyl group which may have a substituent is preferable, and a linear or branched alkyl group or a linear or branched fluorinated alkyl group is more preferable.
• the chain-like alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and still more preferably 1 to 3 carbon atoms.
• the smaller the number of carbon atoms of the chain-like alkyl group for R 104 and R 105 the more the solubility in a resist solvent is improved. Further, in the chain-like alkyl group for R 104 and R 105 , it is preferable that the number of hydrogen atoms substituted with fluorine atoms is as large as possible because the acid strength increases and the transparency to high energy radiation of 200 nm or less or electron beam is improved.
• the fluorination ratio of the chain-like alkyl group is preferably from 70 to 100%, more preferably from 90 to 100%, and it is particularly desirable that the chain-like alkyl group be a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms.
• V 102 and V 103 each independently represents a single bond, an alkylene group or a fluorinated alkylene group, and is the same as defined for V 101 in formula (b-1).
• L 101 and L 102 each independently represents a single bond or an oxygen atom.
• R 106 to R 108 each independently represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent or a chain alkenyl group which may have a substituent, and is the same as defined for R′ 201 .
• L 103 to L 105 each independently represents a single bond, —CO— or —SO 2 —.
• m represents an integer of 1 or more
• M′ m+ represents an onium cation having a valency of m, preferably a sulfonium cation or an iodonium cation, and examples thereof include an organic cation represented by any one of the aforementioned general formulae (ca-1) to (ca-5).
• preferable cations represented by the aforementioned formula (ca-1) include cations represented by the aforementioned formulae (ca-1-1) to (ca-1-127).
• preferable cations represented by the aforementioned formula (ca-2) include a dihphenyliodonium cation and a bis(4-tert-butylphenyl)iodonium cation.
• preferable cations represented by the aforementioned formula (ca-3) include cations represented by the aforementioned formulae (ca-3-1) to (ca-3-6).
• preferable cations represented by the aforementioned formula (ca-4) include cations represented by the aforementioned formulae (ca-4-1) and (ca-4-2).
• preferable cations represented by the aforementioned formula (ca-5) include cations represented by the aforementioned formulae (ca-5-1) to (ca-5-3).
• a cation represented by general formula (ca-1) is preferable, and a cation represented by any one of formulae (ca-1-1) to (ca-1-127) is more preferable.
• the component (B2) one kind of compound may be used, or two or more kinds of compounds may be used in combination.
• the amount of the component (B2) relative to 100 parts by weight of the component (A) is preferably 50 parts by weight or less, more preferably 1 to 40 parts by weight, and still more preferably 5 to 30 parts by weight.
• the amount of the component (B2) is within the above-mentioned range, formation of a resist pattern may be satisfactorily performed. Further, by virtue of the above-mentioned range, when each of the components are dissolved in an organic solvent, a homogeneous solution may be more reliably obtained and the storage stability of the resist composition becomes satisfactory.
• the resist composition of the present embodiment may contain, in addition to the aforementioned components (A) and (B), any other optional components.
• optional components include the component (D), the component (E), the component (F) and the component (S) described below.
• the resist composition of the present invention may include, in addition to the components (A) and (B), an acid diffusion control component (hereafter, sometimes referred to as “component (D)”).
• component (D) functions as an acid diffusion control agent, i.e., a quencher which traps the acid generated in the resist composition upon exposure.
• component (D) examples include a photodecomposable base (D1) (hereafter, referred to as “component (D1)”) which is decomposed upon exposure and then loses the ability of controlling of acid diffusion, and a nitrogen-containing organic compound (D2) (hereafter, referred to as “component (D2)”) which does not fall under the definition of component (D1).
• component (D1) a photodecomposable base
• component (D2) a nitrogen-containing organic compound
• the component (D1) is not particularly limited, as long as it is decomposed upon exposure and then loses the ability of controlling of acid diffusion.
• As the component (D1) at least one compound selected from the group consisting of a compound represented by general formula (d1-1) shown below (hereafter, referred to as “component (d1-1)”), a compound represented by general formula (d1-2) shown below (hereafter, referred to as “component (d1-2)”) and a compound represented by general formula (d1-3) shown below (hereafter, referred to as “component (d1-3)”) is preferably used.
• the components (d1-1) to (d1-3) are decomposed and then lose the ability of controlling of acid diffusion (i.e., basicity), and therefore the components (d1-1) to (d1-3) cannot function as a quencher, whereas at unexposed portions of the resist film, the components (d1-1) to (d1-3) functions as a quencher.
• Rd 1 to Rd 4 represent a cyclic group which may have a substituent, a chain alkyl group which may have a substituent or a chain alkenyl group which may have a substituent, provided that, the carbon atom adjacent to the sulfur atom within the Rd 2 in the formula (d1-2) has no fluorine atom bonded thereto;
• Yd 1 represents a single bond or a divalent linking group;
• m represents an integer of 1 or more; and each M m+ independently represents an organic cation having a valency of m.
• Rd 1 represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent or a chain alkenyl group which may have a substituent, and is the same groups as those defined above for R′ 201 .
• an aromatic hydrocarbon group which may have a substituent an aliphatic cyclic group which may have a substituent and a chain-like alkyl group which may have a substituent are preferable.
• substituent for these groups include a hydroxy group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, a lactone-containing cyclic group represented by any one of the aforementioned formulae (a2-r-1) to (a2-r-7), an ether bond, an ester bond, and a combination thereof.
• the substituent may be bonded via an alkylene group, and a linking group represented by any one of the aforementioned formulae (y-a1-1) to (y-a1-5) is preferable as the substituent.
• the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure containing a bicyclooctane skeleton (a polycyclic structure constituted of a bicyclooctane skeleton and a ring structure other than bicyclooctane).
• Examples of the aliphatic cyclic group include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbomane, isobomane, tricyclodecane or tetracyclododecane.
• the chain-like alkyl group preferably has 1 to 10 carbon atoms, and specific examples thereof include a linear alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl or a decyl group, and a branched alkyl group such as a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group or a 4-methylpentyl group.
• a linear alkyl group such as a
• the chain-like alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group
• the fluorinated alkyl group preferably has 1 to 11 carbon atoms, more preferably 1 to 8 carbon atoms, and still more preferably 1 to 4 carbon atoms.
• the fluorinated alkyl group may contain an atom other than fluorine. Examples of the atom other than fluorine include an oxygen atom, a sulfur atom and a nitrogen atom.
• a fluorinated alkyl group in which part or all of the hydrogen atoms constituting a linear alkyl group have been substituted with fluorine atom(s) is preferable, and a fluorinated alkyl group in which all of the hydrogen atoms constituting a linear alkyl group have been substituted with fluorine atoms (i.e., a linear perfluoroalkyl group) is particularly desirable.
• M m+ represents an organic cation having a valency of m.
• the organic cation for M m+ for example, the same cation moieties as those represented by the aforementioned formulae (ca-1) to (ca-5) are preferable, cation moieties represented by the aforementioned general formulae (ca-1) is preferable, and cation moieties represented by the aforementioned formulae (ca-1-1) to (ca-1-127) are still more preferable.
• one kind of compound may be used, or two or more kinds of compounds may be used in combination.
• Rd 2 represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent or a chain alkenyl group which may have a substituent, and is the same groups as those defined above for R′ 201 .
• the carbon atom adjacent to the sulfur atom within the Rd 2 has no fluorine atom bonded thereto.
• the anion of the component (d1-2) becomes an appropriately weak acid anion, thereby improving the quenching ability of the component (D).
• a chain-like alkyl group which may have a substituent or an aliphatic cyclic group which may have a substituent is preferable.
• the chain-like alkyl group preferably has 1 to 10 carbon atoms, and more preferably 3 to 10 carbon atoms.
• the aliphatic cyclic group a group in which one or more hydrogen atoms have been removed from adamantane, norbomane, isobomane, tricyclodecane, tetracyclododecane or camphor (which may have a substituent) is more preferable.
• the hydrocarbon group for Rd 2 may have a substituent.
• substituent the same groups as those described above for substituting the hydrocarbon group (e.g., aromatic hydrocarbon group, aliphatic cyclic group, chain-like alkyl group) for Rd 1 in the formula (d1-1) can be mentioned.
• M m+ is an organic cation having a valency of m, and is the same as defined for M m+ in the aforementioned formula (d1-1).
• one type of compound may be used, or two or more types of compounds may be used in combination.
• Rd 3 represents a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent or a chain-like alkenyl group which may have a substituent, and is the same groups as those defined above for R′ 201 , and a cyclic group containing a fluorine atom, a chain alkyl group or a chain alkenyl group is preferable.
• a fluorinated alkyl group is preferable, and more preferably the same fluorinated alkyl groups as those described above for Rd 1 .
• Rd 4 represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent or a chain alkenyl group which may have a substituent, and is the same groups as those defined above for R′ 201 .
• an alkyl group which may have substituent an alkoxy group which may have substituent, an alkenyl group which may have substituent or a cyclic group which may have substituent is preferable.
• the alkyl group for Rd 4 is preferably a linear or branched alkyl group of 1 to 5 carbon atoms, and specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group.
• Part of the hydrogen atoms within the alkyl group for Rd 4 may be substituted with a hydroxy group, a cyano group or the like.
• the alkoxy group for Rd 4 is preferably an alkoxy group of 1 to 5 carbon atoms, and specific examples thereof include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group and a tert-butoxy group. Among these, a methoxy group and an ethoxy group are preferable.
• the alkenyl group for Rd 4 is the same as defined for the alkenyl group for R′ 201 and a vinyl group, a propenyl group (an allyl group), a 1-methylpropenyl group or a 2-methylpropenyl group is preferable. These groups may have an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms as a substituent.
• cyclic group for Rd 4 the same groups as those described above for R′ 201 may be mentioned.
• the cyclic group an alicyclic group (e.g., a group in which one or more hydrogen atoms have been removed from a cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobomane, tricyclodecane or tetracyclododecane) or an aromatic group (e.g., a phenyl group or a naphthyl group) is preferable.
• a cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobomane, tricyclodecane or tetracyclododecane
• aromatic group e.g., a phenyl group or a naphthyl group
• the resist composition When Rd 4 is an alicyclic group, the resist composition can be satisfactorily dissolved in an organic solvent, thereby improving the lithography properties.
• the resist composition when Rd 4 is an aromatic group, the resist composition exhibits an excellent photoabsorption efficiency in a lithography process using EUV or the like as the exposure source, thereby resulting in the improvement of the sensitivity and the lithography properties.
• Yd 1 represents a single bond or a divalent linking group.
• the divalent linking group for Yd 1 is not particularly limited, and examples thereof include a divalent hydrocarbon group (aliphatic hydrocarbon group, or aromatic hydrocarbon group) which may have a substituent and a divalent linking group containing a hetero atom.
• the divalent linking groups are the same as defined for the divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom explained above as the divalent linking group for Ya 21 in the aforementioned formula (a2-1).
• Yd 1 a carbonyl group, an ester bond, an amide bond, an alkylene group or a combination of these is preferable.
• alkylene group a linear or branched alkylene group is more preferable, and a methylene group or an ethylene group is still more preferable.
• M m+ is an organic cation having a valency of m, and is the same as defined for M m+ in the aforementioned components (d1-1).
• one type of compound may be used, or two or more types of compounds may be used in combination.
• component (D1) one type of the aforementioned components (d1-1) to (d1-3), or at least two types of the aforementioned components (d1-1) to (d1-3) can be used in combination.
• the amount of the component (D1) relative to 100 parts by weight of the component (A) is preferably within a range from 0.5 to 20 parts by weight, more preferably from 1 to 15 parts by weight, and still more preferably from 5 to 10 parts by weight.
• the amount of the component (D1) is at least as large as the lower limit of the above-mentioned range, excellent lithography properties and excellent resist pattern shape can be more reliably obtained.
• the amount of the component (D1) is no more than the upper limit of the above-mentioned range, sensitivity can be maintained at a satisfactory level, and through-put becomes excellent.
• the production methods of the components (d1-1) and (d1-2) are not particularly limited, and the components (d1-1) and (d1-2) can be produced by conventional methods.
• the production method of the component (d1-3) is not particularly limited, and the component (d1-3) can be produced in the same manner as disclosed in US2012-0149916.
• the acid diffusion control component may contain a nitrogen-containing organic compound (D2) (hereafter, referred to as component (D2)) which does not fall under the definition of component (D1).
• D2 nitrogen-containing organic compound
• the component (D2) is not particularly limited, as long as it functions as an acid diffusion control agent, and does not fall under the definition of the component (D1).
• any of the conventionally known compounds may be selected for use. Among these, an aliphatic amine is preferable, and a secondary aliphatic amine or tertiary aliphatic amine is more preferable.
• An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.
• aliphatic amines examples include amines in which at least one hydrogen atom of ammonia (NH 3 ) has been substituted with an alkyl group or hydroxyalkyl group of no more than 12 carbon atoms (i.e., alkylamines or alkylalcoholamines), and cyclic amines.
• NH 3 hydrogen atom of ammonia
• alkylamines and alkylalcoholamines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-hexylamine, tri-n-pentylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkyl alcohol amines such as diethanolamine, triethanolamine, di
• Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom.
• the heterocyclic compound may be a monocyclic compound (aliphatic monocyclic amine), or a polycyclic compound (aliphatic polycyclic amine).
• aliphatic monocyclic amine examples include piperidine, and piperazine.
• the aliphatic polycyclic amine preferably has 6 to 10 carbon atoms, and specific examples thereof include 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.
• Examples of other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris ⁇ 2-(2-methoxyethoxy)ethyl ⁇ amine, tris ⁇ 2-(2-methoxymethoxyethyl ⁇ amine, tris ⁇ 2-(1-methoxyethoxy)ethyl ⁇ amine, tris ⁇ 2-(1-ethoxyethoxy)ethyl ⁇ amine, tris ⁇ 2-(1-ethoxypropoxy)ethyl ⁇ amine, tris[2- ⁇ 2-(2-hydroxyethoxy)ethoxy ⁇ ethyl]amine and triethanolamine triacetate, and triethanolamine triacetate is preferable.
• an aromatic amine may be used as the component (D2).
• aromatic amines examples include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole and derivatives thereof, as well as tribenzylamine, 2,6-diisopropylaniline and N-tert-butoxycarbonylpyrrolidine.
• component (D2) one kind of compound may be used, or two or more kinds of compounds may be used in combination.
• the amount of the component (D2) is typically used in an amount within a range from 0.01 to 5 parts by weight, relative to 100 parts by weight of the component (A).
• the amount of the component (D) is within the above-mentioned range, the shape of the resist pattern and the post exposure stability of the latent image formed by the pattern-wise exposure of the resist layer are improved.
• At least one compound (E) (hereafter referred to as the component (E)) selected from the group consisting of an organic carboxylic acid, or a phosphorus oxo acid or derivative thereof may be added.
• Suitable organic carboxylic acids include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid.
• Examples of phosphorus oxo acids include phosphoric acid, phosphonic acid and phosphinic acid. Among these, phosphonic acid is particularly desirable.
• oxo acid derivatives include esters in which a hydrogen atom within the above-mentioned oxo acids is substituted with a hydrocarbon group.
• hydrocarbon group include an alkyl group of 1 to 5 carbon atoms and an aryl group of 6 to 15 carbon atoms.
• phosphoric acid derivatives examples include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.
• phosphonic acid derivatives include phosphonic acid esters such as dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate and dibenzyl phosphonate.
• phosphinic acid derivatives include phosphinic acid esters and phenylphosphinic acid.
• the component (E) one kind of compound may be used, or two or more kinds of compounds may be used in combination.
• the amount of the component (E) is typically used in an amount within a range from 0.01 to 5 parts by weight, relative to 100 parts by weight of the component (A).
• the resist composition may further include a fluorine additive (hereafter, referred to as “component (F)”) for imparting water repellency to the resist film.
• component (F) a fluorine additive
• component (F) for example, a fluorine-containing polymeric compound described in Japanese Unexamined Patent Application, First Publication No. 2010-002870, Japanese Unexamined Patent Application, First Publication No. 2010-032994, Japanese Unexamined Patent Application, First Publication No. 2010-277043, Japanese Unexamined Patent Application, First Publication No. 2011-13569, and Japanese Unexamined Patent Application, First Publication No. 2011-128226 can be used.
• the component (F) include polymers having a structural unit (f1) represented by general formula (f1-1) shown below.
• a polymer (homopolymer) consisting of a structural unit (f1) represented by formula (f1-1) shown below; a copolymer of the structural unit (f1) and the aforementioned structural unit (a1); and a copolymer of the structural unit (f1), a structural unit derived from acrylic acid or methacrylic acid and the aforementioned structural unit (a1) are preferable.
• a structural unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate or a structural unit derived from 1-methyl-1-adamantyl (meth)acrylate is preferable.
• component (F) examples include polymers having a structural unit (f2) represented by general formula (f1-2) shown below.
• a polymer (homopolymer) consisting of a structural unit (f2) represented by formula (f1-2) shown below; and a copolymer of the structural unit (f2) and the aforementioned structural unit (a4) are preferable.
• a structural unit (a4) copolymerized with the structural unit (f2) a structural unit represented by any one of the aforementioned formulae (a4-1) to (a4-7) is preferable, and a structural unit represented by the aforementioned general formula (a4-2) is more preferable.
• R is the same as defined above;
• Rf 102 and Rf 103 each independently represents a hydrogen atom, a halogen atom, an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms, provided that Rf 102 and Rf 103 may be the same or different;
• nf 1 represents an integer of 0 to 5;
• Rf 101 represents an organic group containing a fluorine atom;
• Rf 11 and Rf 12 each independently represents a hydrogen atom, an alkyl group of 1 to 4 carbon atoms or a fluorinated alkyl group of 1 to 4 carbon atoms;
• Rf 13 represents a fluorine atom or a fluorinated alkyl group having 1 to 4 carbon atoms; and
• Rf 14 represents a linear or branched alkyl group of 1 to 4 carbon atoms or a linear fluorinated alkyl group of 1 to 4 carbon atoms.
• R bonded to the carbon atom on the ⁇ -position is the same as defined above.
• R a hydrogen atom or a methyl group is preferable.
• examples of the halogen atom for Rf 102 and Rf 103 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is particularly desirable.
• examples of the alkyl group of 1 to 5 carbon atoms for Rf 102 and Rf 103 include the same alkyl group of 1 to 5 carbon atoms as those described above for R, and a methyl group or an ethyl group is preferable.
• halogenated alkyl group of 1 to 5 carbon atoms represented by Rf 102 or Rf 103 include groups in which part or all of the hydrogen atoms of the aforementioned alkyl groups of 1 to 5 carbon atoms have been substituted with halogen atoms.
• halogen atom examples include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is particularly desirable.
• a hydrogen atom, a fluorine atom or an alkyl group of 1 to 5 carbon atoms is preferable, and a hydrogen atom, a fluorine atom, a methyl group or an ethyl group is more preferable.
• nf 1 represents an integer of 1 to 5, preferably an integer of 1 to 3, and more preferably 1 or 2.
• Rf 101 represents an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom.
• the hydrocarbon group containing a fluorine atom may be linear, branched or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms.
• the hydrocarbon group having a fluorine atom has 25% or more of the hydrogen atoms within the hydrocarbon group fluorinated, more preferably 50% or more, and most preferably 60% or more, as the hydrophobicity of the resist film during immersion exposure is enhanced.
• Rf 101 a fluorinated hydrocarbon group of 1 to 6 carbon atoms is preferable, and a trifluoromethyl group, —CH 2 —CF 3 , —CH 2 —CF 2 —CF 3 , —CH(CF 3 ) 2 , —CH 2 —CH 2 —CF 3 , and —CH 2 —CH 2 —CF 2 —CF 2 —CF 3 are most preferable.
• R bonded to the carbon atom on the ⁇ -position is the same as defined above.
• R a hydrogen atom or a methyl group is preferable.
• Rf 11 and Rf 12 each independently represents a hydrogen atom, an alkyl group of 1 to 4 carbon atoms or a fluorinated alkyl group of 1 to 4 carbon atoms.
• the alkyl group of 1 to 4 carbon atoms for Rf 11 and Rf 12 may be linear, branched or cyclic, and a linear or branched alkyl group is preferable. Specific examples thereof include a methyl group and an ethyl group, and an ethyl group is particularly desirable.
• the fluorinated alkyl group of 1 to 4 carbon atoms for Rf 11 and Rf 12 is an alkyl group of 1 to 4 carbon atoms in which part or all of the hydrogen atoms have been substituted with a fluorine atom.
• the alkyl group prior to being substituted with a fluorine atom may be linear, branched or cyclic, and examples thereof include the same groups as those described above for the “alkyl group of 1 to 4 carbon atoms for Rf 11 and Rf 12 ”.
• Rf 11 and Rf 12 a hydrogen atom or an alkyl group of 1 to 4 carbon atoms is preferable, and it is more preferable that one of Rf 11 and Rf 112 represents a hydrogen atom, and the other represents an alkyl group of 1 to 4 carbon atoms.
• Rf 13 represents a fluorine atom or a fluorinated alkyl group of 1 to 4 carbon atoms.
• the fluorinated alkyl group of 1 to 4 carbon atoms represented by Rf 13 is the same as defined for the “fluorinated alkyl group of 1 to 4 carbon atoms for Rf 11 and Rf 12 ” preferably having 1 to 3 carbon atoms, and more preferably having 1 or 2 carbon atoms.
• the percentage of the number of fluorine atoms based on the total number of hydrogen atoms and fluorine atoms is preferably 30 to 100%, and more preferably 50 to 100%. The higher the fluorination ratio, the higher the hydrophobicity of the resist film.
• Rf 14 represents a linear or branched alkyl group of 1 to 4 carbon atoms or a linear fluorinated alkyl group of 1 to 4 carbon atoms, and a linear alkyl group of 1 to 4 carbon atoms or a linear fluorinated alkyl group of 1 to 4 carbon atoms is preferable.
• alkyl group for Rf 14 examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group and a tert-butyl group.
• a methyl group or an ethyl group is preferable, and a methyl group is particularly desirable.
• preferable fluorinated alkyl group for Rf 14 include —CH 2 —CF 3 , —CH 2 —CH 2 —CF 3 , —CH 2 —CF 2 —CF 3 and —CH 2 —CF 2 —CF 2 —CF 3 .
• —CH 2 —CH 2 —CF 3 or —CH 2 —CF 3 is more preferable.
• the weight average molecular weight (Mw) (the polystyrene equivalent value determined by gel permeation chromatography) of the component (F) is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and most preferably 10,000 to 30,000.
• Mw the polystyrene equivalent value determined by gel permeation chromatography
• the resist composition exhibits a satisfactory solubility in a resist solvent.
• the weight average molecular weight is at least as large as the lower limit of the above-mentioned range, dry etching resistance and the cross-sectional shape of the resist pattern becomes satisfactory.
• the dispersity (Mw/Mn) of the component (F) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5.
• the component (F) one kind of compound may be used, or two or more kinds of compounds may be used in combination.
• the component (F) is used in an amount within a range from 0.5 to 10 parts by weight, relative to 100 parts by weight of the component (A).
• the resist composition of the present embodiment may be prepared by dissolving the resist materials for the resist composition in an organic solvent (hereafter, referred to as “component (S)”).
• the component (S) may be any organic solvent which can dissolve the respective components to give a homogeneous solution, and any organic solvent can be appropriately selected from those which have been conventionally known as solvents for a chemically amplified resist composition.
• lactones such as ⁇ -butyrolactone
• ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone
• polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol and dipropylene glycol
• compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, and dipropylene glycol monoacetate
• polyhydric alcohol derivatives including compounds having an ether bond, such as a monoalkylether (e.g., monomethylether, monoethylether, monopropylether or monobutylether) or monophenylether of any of these polyhydric alcohols or compounds having an ester bond (among these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl
• one kind of solvent may be used, or two or more kinds of compounds may be used as a mixed solvent.
• PGMEA PGMEA
• PGME ⁇ -butyrolactone
• EL cyclohexanone
• a mixed solvent obtained by mixing PGMEA with a polar solvent is preferable.
• the mixing ratio (weight ratio) of the mixed solvent can be appropriately determined, taking into consideration the compatibility of the PGMEA with the polar solvent, but is preferably in the range of 1:9 to 9:1, more preferably from 2:8 to 8:2.
• the PGMEA:EL or cyclohexanone weight ratio is preferably from 1:9 to 9:1, and more preferably from 2:8 to 8:2.
• the PGMEA:PGME weight ratio is preferably from 1:9 to 9:1, more preferably from 2:8 to 8:2, and still more preferably 3:7 to 7:3.
• a mixed solvent of PGMEA, PGME and cyclohexanone is also preferable.
• a mixed solvent of at least one of PGMEA and EL with ⁇ -butyrolactone is also preferable.
• the mixing ratio (former:latter) of such a mixed solvent is preferably from 70:30 to 95:5.
• the amount of the component (S) is not particularly limited, and is appropriately adjusted to a concentration which enables coating of a coating solution to a substrate.
• the component (S) is used in an amount such that the solid content of the resist composition becomes within the range from 1 to 20% by weight, and preferably from 2 to 15% by weight.
• miscible additives can also be added to the resist composition of the present invention.
• miscible additives include additive resins for improving the performance of the resist film, dissolution inhibitors, plasticizers, stabilizers, colorants, halation prevention agents, and dyes.
• the resist composition of the present embodiment as described above contains a resin component (A1) having a structural unit (a0) represented by general formula (a0-1).
• a resin component (A1) having a structural unit (a0) represented by general formula (a0-1).
• the amount of the structural unit (a0) within the component (A1) being more than 30 mol %, the polarity of the resin is increased by the action of acid, and solubility of the resin in a developing solution is improved.
• the resolution is improved at portions near the substrate interface where light may be difficult to reach by exposure.
• the resin in combination with an acid generator having an anion moiety with a specific structure the dissolution contrast between the exposed portions of the resist film and the unexposed portions of the resist film.
• roughness may be reduced, trailing of the pattern may be improved, and a minute pattern having an improved shape with high rectangularity may be formed.
• the method of forming a resist pattern according to the present embodiment includes: step (i) of forming a resist film on a substrate using the aforementioned resist composition; step (ii) of conducting exposure of the resist film; and step (iii) of developing the resist film to form a resist pattern.
• the method for forming a resist pattern according to the present embodiment can be performed, for example, as follows.
• a resist composition of the first aspect is applied to a substrate using a spinner or the like, and a bake treatment (post applied bake (PAB)) is conducted at a temperature of 80 to 150° C. for 40 to 120 seconds, preferably 60 to 90 seconds, to form a resist film.
• a bake treatment post applied bake (PAB)
• PAB post applied bake
• baking treatment post exposure baking (PEB) is conducted under temperature conditions of 80 to 150° C. for 40 to 120 seconds, and preferably 60 to 90 seconds.
• the developing treatment is conducted using an alkali developing solution in the case of an alkali developing process, and a developing solution containing an organic solvent (organic developing solution) in the case of a solvent developing process.
• the rinse treatment is preferably conducted using pure water in the case of an alkali developing process, and a rinse solution containing an organic solvent in the case of a solvent developing process.
• the developing solution or the rinse liquid remaining on the pattern can be removed by a treatment using a supercritical fluid.
• bake treatment post bake
• the substrate is not specifically limited and a conventionally known substrate can be used.
• substrates for electronic components and such substrates having wiring patterns formed thereon can be used.
• Specific examples of the material of the substrate include metals such as silicon wafer, copper, chromium, iron and aluminum; and glass.
• Suitable materials for the wiring pattern include copper, aluminum, nickel, and gold.
• any one of the above-mentioned substrates provided with an inorganic and/or organic film on the surface thereof may be used.
• an inorganic antireflection film inorganic BARC
• an organic antireflection film organic BARC
• an organic film such as a lower-layer organic film used in a multilayer resist method can be used.
• a “multilayer resist method” is method in which at least one layer of an organic film (lower-layer organic film) and at least one layer of a resist film (upper resist film) are provided on a substrate, and a resist pattern formed on the upper resist film is used as a mask to conduct patterning of the lower-layer organic film.
• This method is considered as being capable of forming a pattern with a high aspect ratio. More specifically, in the multilayer resist method, a desired thickness can be ensured by the lower-layer organic film, and as a result, the thickness of the resist film can be reduced, and an extremely fine pattern with a high aspect ratio can be formed.
• the multilayer resist method is broadly classified into a method in which a double-layer structure consisting of an upper-layer resist film and a lower-layer organic film is formed (double-layer resist method), and a method in which a multilayer structure having at least three layers consisting of an upper-layer resist film, a lower-layer organic film and at least one intermediate layer (thin metal film or the like) provided between the upper-layer resist film and the lower-layer organic film (triple-layer resist method).
• the wavelength to be used for exposure is not particularly limited and the exposure can be conducted using radiation such as ArF excimer laser, KrF excimer laser, F2 excimer laser, extreme ultraviolet rays (EUV), vacuum ultraviolet rays (VUV), electron beam (EB), X-rays, and soft X-rays.
• the resist composition is effective for KrF excimer laser, ArF, EB or EUV, and more effective for ArF excimer laser, EB or EUV.
• the exposure of the resist film may be either a general exposure (dry exposure) conducted in air or an inert gas such as nitrogen, or immersion exposure (immersion lithography).
• the method of forming a resist pattern according to the present embodiment may be particularly effective in subjecting the resist film to immersion lithography.
• the region between the resist film and the lens at the lowermost point of the exposure apparatus is pre-filled with a solvent (immersion medium) that has a larger refractive index than the refractive index of air, and the exposure (immersion exposure) is conducted in this state.
• a solvent immersion medium
• the immersion medium preferably exhibits a refractive index larger than the refractive index of air but smaller than the refractive index of the resist film to be exposed.
• the refractive index of the immersion medium is not particularly limited as long as it satisfies the above-mentioned requirements.
• Examples of this immersion medium which exhibits a refractive index that is larger than the refractive index of air but smaller than the refractive index of the resist film include water, fluorine-based inert liquids, silicon-based solvents and hydrocarbon-based solvents.
• the fluorine-based inert liquids include liquids containing a fluorine-based compound such as C 3 HCl 2 F 5 , C 4 F 9 OCH 3 , C 4 F 9 OC 2 H 5 or C 5 H 3 F 7 as the main component, which have a boiling point within a range from 70 to 180° C. and preferably from 80 to 160° C.
• a fluorine-based inert liquid having a boiling point within the above-mentioned range is advantageous in that the removal of the immersion medium after the exposure can be conducted by a simple method.
• a perfluoroalkyl compound in which all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms is particularly desirable.
• these perfluoroalkyl compounds include perfluoroalkylether compounds and perfluoroalkylamine compounds.
• a suitable perfluoroalkylether compound is perfluoro(2-butyl-tetrahydrofuran) (boiling point 102° C.), and an example of a suitable perfluoroalkylamine compound is perfluorotributylamine (boiling point 174° C.).
• water is preferable in terms of cost, safety, environment and versatility.
• TMAH tetramethylammonium hydroxide
• any of the conventional organic solvents can be used which are capable of dissolving the component (A) (prior to exposure).
• the organic solvent include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents and ether solvents, and hydrocarbon solvents.
• a ketone solvent is an organic solvent containing C—C( ⁇ O)—C within the structure thereof.
• An ester solvent is an organic solvent containing C—C( ⁇ O)—O—C within the structure thereof.
• An alcohol solvent is an organic solvent containing an alcoholic hydroxy group in the structure thereof.
• An “alcoholic hydroxy group” refers to a hydroxy group bonded to a carbon atom of an aliphatic hydrocarbon group.
• a nitrile solvent is an organic solvent containing a nitrile group in the structure thereof.
• An amide solvent is an organic solvent containing an amide group within the structure thereof.
• An ether solvent is an organic solvent containing C—O—C within the structure thereof.
• organic solvents have a plurality of the functional groups which characterizes the aforementioned solvents within the structure thereof.
• the organic solvent can be classified as any type of the solvent having the characteristic functional group.
• diethyleneglycol monomethylether can be classified as either an alcohol solvent or an ether solvent.
• a hydrocarbon solvent consists of a hydrocarbon which may be halogenated, and does not have any substituent other than a halogen atom.
• the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is preferable.
• organic solvent contained in the organic developing solution among these, a polar solvent is preferable, and ketone solvents, ester solvents and nitrile solvents are preferable.
• ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonylalcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, propylenecarbonate, ⁇ -butyrolactone and methyl amyl ketone (2-heptanone).
• a ketone solvent methyl amyl ketone (2-heptanone) is preferable.
• ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-me
• nitrile solvents examples include acetonitrile, propionitrile, valeronitrile, butyronitrile and the like.
• the organic developing solution may have a conventional additive blended.
• the additive include surfactants.
• the surfactant is not particularly limited, and for example, an ionic or non-ionic fluorine and/or silicon surfactant can be used.
• a non-ionic surfactant is preferable, and a non-ionic fluorine surfactant or a non-ionic silicon surfactant is more preferable.
• the amount thereof based on the total amount of the organic developing solution is generally 0.001 to 5% by weight, preferably 0.005 to 2% by weight, and more preferably 0.01 to 0.5% by weight.
• the developing treatment can be performed by a conventional developing method.
• a conventional developing method examples thereof include a method in which the substrate is immersed in the developing solution for a predetermined time (a dip method), a method in which the developing solution is cast up on the surface of the substrate by surface tension and maintained for a predetermined period (a puddle method), a method in which the developing solution is sprayed onto the surface of the substrate (spray method), and a method in which the developing solution is continuously ejected from a developing solution ejecting nozzle while scanning at a constant rate to apply the developing solution to the substrate while rotating the substrate at a constant rate (dynamic dispense method).
• a dip method a method in which the developing solution is cast up on the surface of the substrate by surface tension and maintained for a predetermined period
• spray method a method in which the developing solution is sprayed onto the surface of the substrate
• dynamic dispense method a method in which the developing solution is continuously ejected from a developing solution ejecting
• any of the aforementioned organic solvents contained in the organic developing solution can be used which hardly dissolves the resist pattern.
• at least one solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents is used.
• at least one solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents and amide solvents is preferable, more preferably at least one solvent selected from the group consisting of alcohol solvents and ester solvents, and an alcohol solvent is particularly desirable.
• the alcohol solvent used for the rinse liquid is preferably a monohydric alcohol of 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched or cyclic. Specific examples thereof include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol and benzyl alcohol. Among these, 1-hexanol, 2-heptanol and 2-hexanol are preferable, and 1 hexanol and 2-hexanol are more preferable.
• the organic solvent one kind of solvent may be used alone, or two or more kinds of solvents may be used in combination. Further, an organic solvent other than the aforementioned examples or water may be mixed together. However, in consideration of the development characteristics, the amount of water within the rinse liquid, based on the total amount of the rinse liquid is preferably 30% by weight or less, more preferably 10% by weight or less, still more preferably 5% by weight or less, and most preferably 3% by weight or less.
• the rinse solution may have a conventional additive blended.
• the additive include surfactants.
• the additive include surfactants.
• the surfactant the same surfactants as those described above can be mentioned, a non-ionic surfactant is preferable, and a non-ionic fluorine surfactant or a non-ionic silicon surfactant is more preferable.
• the amount thereof based on the total amount of the rinse liquid is generally 0.001 to 5% by weight, preferably 0.005 to 2% by weight, and more preferably 0.01 to 0.5% by weight.
• the rinse treatment using a rinse liquid can be conducted by a conventional rinse method.
• the rinse method include a method in which the rinse liquid is continuously applied to the substrate while rotating it at a constant rate (rotational coating method), a method in which the substrate is immersed in the rinse liquid for a predetermined time (dip method), and a method in which the rinse liquid is sprayed onto the surface of the substrate (spray method).
• lithography properties may be improved (e.g., roughness may be reduced), and a resist pattern having a good shape and in which the cross-section of the pattern has high rectangularity may be formed.
• the obtained reaction polymer solution was dropwise added to a mixed solvent of n-heptane (Hep) and ethyl acetate (AcOEt) (the content of AcOEt: 20% by weight or more) to precipitate a polymer.
• the precipitated white powder was washed with excess amount of a mixed solvent of Hep and AcOEt (the content of AcOEt: 20% by weight or more), followed by drying, so as to obtain 38.85 g of polymeric compound (A1-1) as an objective compound (yield: 79.28%).
• Polymeric compounds (A1-2) to (A1-6) and (A2-1) to (A2-3) were obtained by conducting radical polymerization in the same manner as in Synthesis Example 1, except that monomers shown in Table 1 were used in a predetermined molar ratio.
• compositional ratio of the polymers (the molar ratio of the respective structural units in the polymeric compound) as determined by 13 C-NMR, the weight average molecular weight (Mw) and the polydispersity (Mw/Mn) determined by the polystyrene equivalent value as measured by GPC are also shown in Table 1.
• the amount of the structural unit (a0) based on total amount (100 mol %) of the structural unit (a0) and the structural unit (a1) is indicated under “(a0)/(a0)+(a1) (mol %)” in Table 1.
• (A)-1 to (A)-6 the aforementioned polymeric compounds (A1-1) to (A1-6).
• (B)-1 to (B)-3 acid generators represented by chemical formulae (B-1), (B-2) and (B-3) shown below, respectively.
• (D)-1 Acid diffusion control agent consisting of a compound represented by chemical formula (D-1) shown below.
• (F)-1 fluorine-containing polymeric compound (homopolymer) represented by chemical formula (F-1) shown below.
• the weight average molecular weight (Mw) and the dispersity (Mw/Mn) in terms of the polystyrene equivalent value measured by gel permeation chromatography (GPC) were 24,000 and 1.38, respectively.
• An organic anti-reflection film composition (product name: ARC95, manufactured by Brewer Science Ltd.) was applied to an 12-inch silicon wafer using a spinner, and the composition was then baked at 205° C. for 60 seconds and dried, thereby forming an organic anti-reflection film having a film thickness of 90 nm.
• each resist composition (Examples 1 to 7 and Comparative Examples 1 to 4) was applied to the organic anti-reflection film using a spinner, and was then prebaked (PAB) on a hot plate at 100° C. for 60 seconds and dried, thereby forming a resist film having a film thickness of 90 nm.
• PAB prebaked
• PEB post exposure bake
• TMAH tetramethylammonium hydroxide
• LS pattern line and space pattern having a line width of 64 nm and a pitch of 112 nm was formed.
• “3 ⁇ ” indicates a value of 3 times the standard deviation ( ⁇ ) (i.e., 30) (unit: nm) determined by measuring the line positions at 400 points in the lengthwise direction of the line using a scanning electron microscope (product name: S-9380, manufactured by Hitachi High-Technologies Corporation; acceleration voltage: 300V).
• the cross-sectional shape of the LS pattern formed in the above “Formation of resist pattern” was observed using a scanning electron microscope (SEM) (product name: SU-8000, manufactured by Hitachi High-Technologies Corporation; acceleration voltage: 8 kV), and the LS pattern shape was evaluated.
• SEM scanning electron microscope

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